Blueprint Hair Peptides Analysis

Blueprint is the health and longevity company started by Bryan Johnson. They mostly sell supplements, but also things like olive oil, honey, powders, and meal-replacements. They are notable for their high level of transparency, providing recent third-party COAs (Certificates of Analysis) for each produc, which disclose both the levels of contaminants and usually the amounts of ingredients¹.

They recently launched a shampoo and hair serum designed to help scalp and hair health and growth. I wanted to explore the evidence behind them and thought you might, too.

Click here for the video version of this article on YouTube.

This article isn’t about hair-loss in general, but before we get to the product review it’s worth briefly addressing how scalp and hair relate to overall health.

Hair and Health

A 2014 analysis of a randomized trial involving 39,070 men found that:

[…] baldness at age 45 years was significantly associated with an increased risk of aggressive prostate cancer compared with no baldness.²

This has been replicated in other research, including in a systematic review and meta-analysis of 7 case-control studies³.

There is an established link between vertex (top of head) baldness and coronary artery disease (atherosclerosis), as shown by a meta-analysis of 856 studies involving 36,990 participants, even in young people⁴.

In fact, a 2017 study found that baldness and premature greying are the strongest predictors of early heart disease, even ahead of obesity⁵.

This suggests a common mechanism behind these diseases and scalp/hair health. It does not suggest that using any topical products would improve risks for those diseases, but it does show that premature baldness and greying are not purely cosmetic.

Hair protects the head from UV radiation⁶ and having skin that is able to recover from wounds becomes increasingly important as we age, which is relevant because some of the ingredients in these products may improve wound-healing.

What is a peptide?

I’ve seen a lot of news about peptides recently in the health and longevity space, to the point of it becoming like a buzzword. Peptides are basically small, simple proteins, as the Encyclopedia Britannica explains in its article What Is the Difference Between a Peptide and a Protein?:

The basic distinguishing factors are size and structure. Peptides are smaller than proteins. […] In addition, peptides tend to be less well defined in structure than proteins […]⁷

Peptides occur naturally in our bodies, and they can also be hormones; insulin and oxytocin are peptides. They can also be pharmaceuticals, with 5 peptides gaining FDA-approval as drugs in 2023⁸

Over the course of researching for this review, it became clear to me that there is a nearly-overwhelming amount of research on peptides, spanning more than a century. The journal Antibiotics did a 2024 special issue titled The Century-Long Journey of Peptide-Based Drugs⁹ that dove into the history from an antimicrobial perspective, noting that the first insulin injection happened in 1922.

Even with that rich history, there isn’t much high-quality evidence in humans for hair and scalp application, especially not topical, let alone liposomal, which is what the Blueprint hair products use to increase absorption rates.¹⁰

What are the Claimed Benefits?

It’s important to know what the specific claims are before evaluating the shampoo and serum.

I pulled the following relevant claims from the Blueprint FAQ website¹¹, there were more claims but I ignored ones that use waffly language like “improves hair quality” and things like that, which was most of the claims.

Some users report differences in the appearance of gray hair, but more research is needed.
Using the products for 6-9 months results in fuller, thicker looking strands and reduced dryness, flakiness and irritation.
Both the Peptide Serum and Peptide Shampoo are free of drugs, hormones, SLS, parabens, gluten, sulfates, animal testing, carcinogens, and fragrance.
Those with a history of skin cancer on the scalp should not use the products.

We will come back and evaluate these claims at the end.

The Ingredients

Here I’ll list the ingredients for each bottle separately, since they are similar but different, and then I will drill into the research for each ingredient in the next section.

It’s worth noting that Blueprint is not disclosing the amounts of ingredients, which was a bit surprising for me because the brand has been built on transparency until now. They publish CoAs and amounts for all of their supplements. They do publish CoAs for these products too¹² ¹³ but they are only for contaminants, not ingredients. That means we are in the position of needing to trust Blueprint, which is something Bryan has famously and repeatedly warned everyone to not do with companies.

I reached out to Blueprint support to see if they would let us know about the amounts, and got this response:

While we share the full list of peptides included in the shampoo and serum, we do not disclose the specific amounts of each ingredient as this is part of our proprietary formulation.

The next sections contain the in-depth analyses of the ingredients. If you would prefer to skip to the conclusion, click here.

Blueprint Peptide Serum

The peptides are:

sh-oligopeptide-1 – EGF
sh-oligopeptide-4 – Thymosin-β4
sh-polypeptide-4 – SCF
sh-polypeptide-7 – hGH
sh-polypeptide-9 – VEGF
sh-Polypeptide-59 – PDGF
sh-Polypeptide-86 – Follistatin
Copper Tripeptide-1 – GHK Tripeptide-1

In addition to the peptides, the ingredients are:

Aqua, Pentylene Glycol, Glycerin, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, DNA (PDRN), Nicotinamide Mononucleotide, Curcumin, Tetrahydrocurcumin, Panthenol, Caffeine, Adenosine, Niacinamide, Arginine, Ketoglutaric Acid, Salicylic Acid, Thioctic Acid, Lecithin, 1,2-Hexanediol, Acetyl Cysteine, Glycine, 3-O-Ethyl Ascorbic Acid, p-Anisic Acid, Polysorbate 60, Sodium Citrate, Citric Acid, Glutathione¹⁴.

Blueprint Peptide Shampoo

The peptides are:

sh-oligopeptide-1 – EGF
sh-oligopeptide-4 – Thymosin-β4
sh-polypeptide-1 – bFGF
sh-polypeptide-7 – hGH
sh-polypeptide-9 – VEGF
sh-polypeptide-11 – aFGF
sh-polypeptide-71 – VIP
Copper Tripeptide-1 – GHK Tripeptide-1

In addition to the peptides, the ingredients are:

Aqua, Lauryl Glucoside, Glycerin, Decyl Glucoside, Coco-Glucoside, Disodium Lauryl Sulfosuccinate, Pentylene Glycol, Lauramidopropyl Betaine, Sodium Cocoyl Apple Amino Acids, Betaine, Glycol Distearate, Polyquaternium-10, Caprylyl/Capryl Glucoside, Niacinamide, 3-O-Ethyl Ascorbic Acid, Adenosine, Caffeine, Arginine, Tetrahydrocurcumin, Curcumin, Menthol, Silk Amino Acids, Tetrasodium Glutamate Diacetate, Mentha Arvensis Herb Oil, Lecithin, Trehalose, Glyceryl Caprylate, Hexylene Glycol, Panthenol, Polysorbate 60, Citric Acid, Sodium Citrate, Sodium Chloride, Phenoxyethanol, Limonene.¹⁵

Analysis

Peptides in both bottles

The bottles share most of their peptides, so this section will look at them together. Then there will be two more sections to cover the remaining peptides.

sh-oligopeptide-1 (EGF)

Epidermal Growth Factor is a popular peptide with decades of research behind it, starting in the 1950s. It is found throughout our bodies and food, as well as other anti-hair loss and hair growth products¹⁶

A 2021 systematic review of 49 articles found that EGF is effective at regenerating wounded skin and inverting skin aging, however they also noted that only 15 of those studies were randomized and controlled, and they found the positive effect was better when its was injected than applied topically, so they were wary about claiming its efficacy as established.

They also noted that penetration may be improved by chemical modification with lipophilic molecules, which is what Blueprint claim to be using with their nanoliposome delivery system.

The researchers also made an interesting statement:

Similarities exist between the aging skin and wound healing, and mostly they involve the same oxidation and repair mechanisms¹⁷

However, it’s not all good news on EGF. One study found that serum EGF correlated with alopecia areata, which is an autoimmune disorder that causes bald patches to appear¹⁸

An older study on sheep showed that high levels of EGF caused wool to stop growing and fall out, as well as rupturing of blood vessels in the dermis¹⁹. So the claim that Bryan Johnson makes that these products contain:

8 biomimetic peptides, more than any other product. And in the highest concentrations.²⁰

is not necessarily a good thing. It would be good to know what the amounts are so we can assess risk.

sh-oligopeptide-4 (Thymosin-β4)

There is a lot of research about Thymosin beta-4 confirming its ability to enhance wound-healing and hair growth²¹.

An article in the European Journal of Dermatology notes that it is effective for accelerated healing and tissue repair, and that it is safe even in frail people.

[…] thymosin β4 has, in the last 20+ years, showed consistent strong effects on promoting tissue repair and regeneration in many diverse organs and in various preclinical models of tissue injury²²

One small study found that it improved seborrheic dermatitis more than ketoconazole, and improved the homeostasis and composition of the scalp microbiota and flora²³

There is also mechanistic evidence of its effects on hair growth and angiogenesis²⁴ which also describes the hair follicle as an important mini‐organ of the skin, consisting of nine distinctive epidermal layers, with this useful diagram:

sh-polypeptide-7 (hGH)

Human Growth Hormone has a long history of use, but usually isn’t used topically because of very poor absorption. However delivery methods like liposomes have been shown to enhance absorption.

A 2023 study showed that topical hGH with an absorption aid significantly improved wound healing and reduced scarring²⁵

At high concentrations (500 ng/mL) of hGH, IGF-1 mRNA expression is down-regulated, while low concentrations (5 ng/ml) caused IGF-1 upregulation²⁶, so it’s very important to get the right dose.

sh-polypeptide-9 (VEGF)

Vascular Endothelial Growth Factor is an interesting choice here, because a lot of the research on it is about how cancer tumors use it to give themselves an advantage, and its role in vision loss.

Targeting VEGF and associated pathways has prevented blindness in millions of patients with eye disease and increased survival/lifespan for patients suffering from a number of different cancer types²⁷.

Here is an overview of the history of VEGF:

VEGF in Signaling and Disease: Beyond Discovery and Development

It’s common for cancers to adapt in those kinds of ways, and doesn’t necessarily mean using topical VEGF is a bad thing. Obviously we don’t want cancers to grow, but we do want healthy cells to grow.

I am more concerned about its effects on eye disease, especially given that parts of it would migrate to the eyes from the scalp and hair while using shampoo in the shower. The suppression of VEGF is a common way to treat vision loss, as seen in this quote from a 2019 review of 16 trials:

Participants treated with any anti‐VEGF agent featured in these trials […] more often gained or maintained visual acuity at one year and less often lost visual acuity compared with participants who received no anti‐VEGF agent.²⁸

Copper Tripeptide-1 (GHK)

GHK (glycyl-l-histidyl-l-lysine) promotes skin remodeling, wound healing and regeneration²⁹. It also stimulates blood vessel and nerve outgrowth, and increases collagen and elastin. GHK is also anti-cancer, anti-inflammatory, restores chronic obstructive pulmonary disease (COPD) fibroblasts, and has anti-aging properties³⁰.

I have used a GHK serum before on my face. It was too expensive to continue using, which is a shame because my skin was really responding to it, so I am a fan of this ingredient.

Serum-only peptides

sh-polypeptide-4 (SCF)

Stem Cell Factor is also known as Mast Cell Growth Factor, KIT-ligand, and Steel Factor. There is research confirming it has a role in melanogenesis, which is the process that produces melanin which darkens skin and hair³¹.

SCF is similar to VEGF in that it is upregulated in cancer cells, in this case particularly mast cell tumors in cats³² and dogs³³. Again, that doesn’t mean that applying it topically would cause cancer, but it is worth being aware of.

sh-Polypeptide-59 (PDGF)

Platelet-Derived Growth Factor is involved in the maintainance of connective tissue, but elevated levels are found in the skin and lungs of people suffering from scleroderma (systemic sclerosis)³⁴ and it is involved in the progression of melanoma³⁵.

Topical application has been found to enhance wound healing³⁶ leading to it being applied to wound dressings³⁷, though that finding has been inconsistent³⁸ and it may induce and maintain hair follicles’ anagen phase in mice³⁹.

Higher concentrations of PDGF receptors are found in chronic skin wounds and psoriasis⁴⁰, and low levels of PDGF correlate with metabolic syndrome, potentially explaining why psoriasis and metabolic syndrome often occur together⁴¹.

sh-Polypeptide-86 (Follistatin)

There’s little to no direct evidence for topical follistatin affecting scalp or hair in humans. There are some studies in mice that suggest it might increase the cycle rate of hair follicles, which would more closely match the rate of younger mice⁴², but those mice are genetically-modified to suppress their follistatin production, so it’s hard to know what the effect could be in humans⁴³.

It’s also not necessarily the case that increasing cell turnover in aging people would be good for their scalp or overall health, and that line of thinking could be a good example of a common logical fallacy in longevity research; there might be good reasons for hair cell turnover slowing with age.

Our bodies are complex and full of mechanisms that maintain homeostasis, so making one specific thing more “youthful” can have unexpected effects. This line of reasoning is summarized in the antagonistic pleiotropy hypothesis⁴⁴. For example, having a youthful immune system as we age can cause autoimmune disorders, as a recent review in Nature Aging explains⁴⁵.

Shampoo-only peptides

sh-polypeptide-1 (bFGF)

Basic Fibroblast Growth Factor has been seen to increase hair follicle size, hair shaft length, and even increase pigmentation via melanin synthesis and increase proliferation of hair follicle stem cells in mice and human cells⁴⁶⁴⁷ ⁴⁸.

That might be a double-edged sword – which is a recurring theme with these growth factors – because it may make melanoma more common when combined with UVB radiation⁴⁹, which is abundant in sunlight.

sh-polypeptide-11 (aFGF)

Acidic Fibroblast Growth Factor is similar to bFGF and promotes the anagen growth phase of hair follicles when injected into mice, but may also slow down hair growth over time, according to a mouse study that found:

Follicles in bFGF-treated areas appeared able to form and develop normally but at a much slower rate. This suppressed state continued until the influence of exogenous FGF was removed […]⁵⁰

There isn’t as much research for aFGF as bFGF, especially for topical use, so it’s hard to say anything conclusive about it.

sh-polypeptide-71 (VIP)

Vasoactive Intestinal Peptide may contribute to maintaining the immune-privilege of hair cells to protect them from autoimmune diseases⁵¹, and it may stimulate hair pigmentation:

VIP treatment significantly promoted intrafollicular melanin production in situ and stimulated melanogenesis […]⁵²

Other ingredients in both bottles

Now I’ll go over the other ingredients. Even though the products are mostly about the peptides, there are other active ingredients worth knowing about and considering.

Aqua

Obviously they both have water, and that’s good.

Pentylene Glycol

This is a common humectant (moisture-retainer) in cosmetics. It’s usually safe but it does cause allergic reactions in a small number of people, which has caused some researchers to suggest it is an adult allergen⁵³. If you do get a skin reaction from these products, this could be why.

Glycerin

This is another common humectant and is considered safe, no worries here⁵⁴.

Curcumin and tetrahydrocurcumin

Curcumin is a popular supplement derived from turmeric. It also shows promise for reducing inflammation and enhancing wound healing when applied to skin, as shown in reviews⁵⁵ ⁵⁶, and being encased in liposomes should improve its absorption, which is typically not very good⁵⁷. Tetrahydrocurcumin is a more bioavailable and stable version of curcumin. I like these ingredients.

Panthenol

This is a derivative of vitamin B5 (pantothenic acid), and when it is absorbed by the body, it becomes vitamin B5 again. It can help with inflammation and eczema⁵⁸. Rates of allergic reactions are uncommon at around 1.2%, but that is enough to be aware of⁵⁹.

Caffeine

Caffeine is another good choice, because it improves circulation, protects cells against UV radiation, and slows down skin photoaging⁶⁰. The Blueprint website claims that it helps “maintain scalp hydration and overall scalp comfort”⁶¹.

Adenosine

Adenosine has been shown to improve hair thickness in Japanese and Caucasian men and women with pattern baldness, with no recorded side-effects⁶²⁶³. This is a great ingredient.

Niacinamide

Niacinamide has become popular in skin products, and there is some evidence it can help increase hair fullness⁶⁴ but there is also research showing that it inhibits hair growth⁶⁵ ⁶⁶ so I’m not sure about this one. Do you want fuller hair that also grows more slowly?

Arginine

Arginine has been seen to enhance wound healing in skin⁶⁷, but there isn’t much research relating to hair or scalp in humans. I found one research paper published by L’Oréal that linked arginine to hair elongation, but obviously it is in their interest to make that finding, so it should be taken with a grain of salt⁶⁸.

Lecithin

Lecithin is commonly used to form liposomes, which are basically blobs of fat similar to cell membranes that encase active ingredients, and protect them from being broken down on their way to cells, which improves their absorption⁶⁹.

As you can see in this image, liposomes have a hydrophilic outer surface layer, a hydrophobic inner surface layer, and a core which is where the real ingredient to be absorbed is.

Image from West Bengal Chemical Industries Limited

3-O-Ethyl Ascorbic Acid

3-O-Ethyl Ascorbic Acid is also known as Vitamin C Ethyl. It’s commonly used as a skin lightener⁷⁰ and there is research hypothesizing that vitamin C in the diet is useful for hair, but everything I could find was in vitro or theoretical⁷¹, so there appears to be a lack of high quality evidence for this one despite its popularity, which was surprising to me.

Polysorbate 60

Polysorbate 60 (polyoxyethylene (20) sorbitan monostearate) is an emulsifier, which means it improves the consistency between oil and water-based ingredients. It is widely used and considered safe⁷².

Sodium Citrate and Citric Acid

Sodium citrate is used as a pH adjuster, chelating agent, and buffering agent. It is generally considered safe⁷³.

Serum-only ingredients

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

This tongue-twister has limited evidence as a stabilizer and may improve absorption of minoxidil⁷⁴ ⁷⁵ so it is an interesting choice for the 4th-highest non-peptide ingredient in the serum. That’s a lot of trust to place in hardly any evidence.

DNA (PDRN)

There is some evidence that polydeoxyribonucleotide can improve wound healing, skin aging, acne scars, and hair loss⁷⁶, with one study concluding that:

[…] PDRN effectively inhibits the aging of keratinocytes cells by upregulating SIRT1 expression and reducing nuclear autophagy when exposed to UVB or H₂O₂-induced senescence including in mice skin.⁷⁷

Nicotinamide Mononucleotide

NMN is one of the most popular and controversial longevity supplements, and has more recently been studied for its effects on scalp and hair. There is promising preliminary evidence that it promotes hair growth and reduces scalp inflammation, especially when combined with other agents and LLLT⁷⁸

Ketoglutaric Acid

Also known as alpha ketogluterate (α-KG), this is another popular supplement that has been shown to increase lifespan and healthspan in mice, including female mice, which isn’t that common⁷⁹. There is also limited evidence that it may improve hair growth by increasing autophagy⁸⁰ but this is really preliminary, non-human evidence.

Salicylic Acid and Menthol

Salicylic acid along with menthol and dexpanthenol has been shown to improve hair thickness, reduce itchiness, and reduce hair loss in people in Korea⁸¹, and in a double-blind randomized placebo-controlled study that also tested panthenol and niacinamide⁸² so these are good additions.

Thioctic Acid

Thioctic Acid is also commonly known as ALA (alpha-lipoic acid). It occurs naturally in food like spinach, broccoli, flaxseeds, chia seeds, and organ meats⁸³. There isn’t much research about its effects on scalp and hair, but there is one study that found it reduced scalp inflammation and therefore could help with hair loss and thinning, when combined with carnitine and saw palmetto extract⁸⁴.

1,2-Hexanediol

The research is lacking on 1,2-Hexanediol, but it is commonly-used in hair products as a preservative to increase shelf-life, and as a humectant⁸⁵. Despite the lack of formal research, it seems to have a good reputation as a skincare ingredient, with only a slight risk of clogging pores⁸⁶.

Acetyl Cysteine

Acetyl Cysteine, also known as N-acetyl-L-cysteine (NAC) is another popular supplement in the longevity space, often paired with glycine in a combination referred to as GlyNAC.

There is one research article in the QJM showing it improves hair density and quality with no reported side-effects⁸⁷ but there are no details about the methodology in the online PDF so I don’t know whether it was used topically or orally, or anything else about the study.

Speaking of pairing it with glycine, the next ingredient is…

Glycine

Similar to NAC, glycine has very little evidence for topical use on scalp or hair. It may be a promising candidate given that it may work to slightly reduce damage from UVA radiation⁸⁸ but more research is needed.

p-Anisic Acid

p-Anisic acid is also known as draconic acid, which is a pretty cool name. It’s a common preservative used in cosmetics, nothing too interesting apart from the name⁸⁹.

Glutathione

The final ingredient for the serum is glutathione, which is another popular supplement, sometimes called the Master Antioxidant. Interestingly there are studies showing it has a positive effect on oxidative stress in hair follicles⁹⁰, and that hair growth is impaired when glutathione is reduced⁹¹.

Shampoo-only ingredients

Lauryl, Decyl, Coco, and Caprylyl/Capryl Glucosides

These ingredients are collectively known as alkyl glucosides, and because they are surfactants, they’re also emulsifiers. They perform the same function as the infamous Sodium Lauryl Sulfate (SLS), but are less irritating. They all have a decent safety profile and are at most mildly-irritating⁹².

One exception is lauryl glucoside, which is safe, but one study showed that it increased hair friction and rigidity⁹³ and was inferior to the other surfactants that were tested, so it’s a bit puzzling that it is the first ingredient in the shampoo behind water.

Disodium Lauryl Sulfosuccinate and Sodium Cocoyl Apple Amino Acids

Disodium lauryl sulfosuccinate (DLS), as the name suggests, is similar to SLS. It is equally as foaming, but unlike SLS it is not a sulfate, making it milder than its irritating molecular cousin⁹⁴. Sodium Cocoyl Apple Amino Acids are the same⁹⁵.

Lauramidopropyl Betaine and Betaine

Lauramidopropyl betaine (LAPB) is similar to DLS, since it is a non-sulfate surfactant. However, there is evidence that it inflames scalp dermatitis in some people⁹⁶ and a systematic review found that another form of betaine causes eczema lesions, itching, and burning sensations in 7% of people⁹⁷, so this is a questionable choice, especially given that there are already milder ingredients in the formulation that perform the same function.

Glycol Distearate

Glycol distearate is basically used to give cosmetics iridescence⁹⁸.

Polyquaternium-10

Polyquaternium-10 adds a thin film to the surface of hair which can make it appear glossy and conditioned. It can also cause other ingredients to stay in the hair longer, as one study showed with hyaluronic acid⁹⁹.

Silk Amino Acids

Silk amino acids are similar to polyquarternium-10, in that they add a thin film, but silk amino acids may also protect against UV damage, and have anti-oxidant, anti-microbial, and anti-tyrosinase activity. Their low molecular weight also gives them good absorption into hair strands and skin cells¹⁰⁰. This seems like a good ingredient.

Tetrasodium Glutamate Diacetate

Tetrasodium glutamate diacetate is also known as glutamic acid diacetate (GLDA) and it’s a chelating agent, which means it binds to metals to prevent oxidation¹⁰¹. Glutamic acid has been shown to promote hair growth in mice¹⁰² but other variants make wounds heal more slowly¹⁰³ so it’s hard to know what the overall effect of this ingredient would be.

Mentha Arvensis Herb Oil

Mentha arvensis (also known as wild mint or cornmint) oil is an ingredient in mosquito repellants and herbal medicine for things like stomach aches and gum health¹⁰⁴. Herbal hair oils in general have been seen to have good effects on hair growth and scalp inflammation¹⁰⁵ and while there isn’t a lot of research on this particular one and scalp or hair, this oil consists of up to 93.7% menthol¹⁰⁶ so it can be expected to also have the benefits of menthol I mentioned earlier in this article.

Trehalose

Trehalose may increase proliferation and decrease cell death in hair cells when exposed to oxidative stress¹⁰⁷ and protect against skin damage¹⁰⁸.

Molecular mechanisms of skin aging, showing the interplay between external and internal factors leading to oxidative stress, extracellular matrix degradation, and visible signs of aging through AGEs-mediated pathways.

In a comprehensive review from 2024, it has been seen to work in combination with hyaluronic acid to enhance skin quality and mitigate inflammation, leading the researchers to conclude that:

The implications of these findings are profound for the future of anti-aging therapeutics in aesthetic medicine, suggesting that the integration of HA and trehalose holds promise for revolutionary advancements in preserving skin vitality and health.¹⁰⁹

Glyceryl Caprylate and Hexylene Glycol

Glyceryl caprylate and hexylene glycol are preservatives and moisturizers. Glyceryl caprylate seems safe in low concentrations¹¹⁰. but hexylene glycol has been seen to cause an allergic reaction in 2.8% of people in a study involving 823 eczema patients¹¹¹.

Sodium Chloride

Sodium chloride (table salt, NaCl) seems like a strange choice here, because it has been seen to correlate with immune responses causing atopic dermatitis (atopic eczema), with researchers noting that:

The skin of patients suffering from atopic dermatitis contained elevated sodium compared to nonlesional atopic and healthy skin.¹¹²

It is usually added to cosmetics as a thickener¹¹³.

Phenoxyethanol

Phenoxyethanol is a stabilizer that is generally regarded as safe for adults by regulatory authorities at 1% concentration¹¹⁴ and has been seen to reduce skin acne in a pilot study¹¹⁵.

However, there is evidence that it may disrupt the endocrine system, resulting in longer pregnancies¹¹⁶, differences in hormone levels in children¹¹⁷, and lower neurocognitive performance in 6-year-olds¹¹⁸ according to data analyzed from the PELAGIE Cohort Study which is a really cool ongoing study on 3421 women and their children in France that has already contributed a wealth of data about the effects of pesticides, solvents and pollutants.

The International Journal of Epidemiology published a great overview of the study called Cohort Profile: The PELAGIE mother-child cohort that I recommend checking out¹¹⁹.

Limonene

Limonene comes from citrus peels and has been associated with a variety of potential health benefits to skin and hair including protecting against UV damage by boosting antioxidant defense systems in the body¹²⁰, inhibiting pro-inflammatory cytokines and itching from eczema in mice¹²¹, and improvements to hair loss in rats¹²². There are a lot of studies about its good effects, but most of them are in non-humans.

It’s regarded as safe in cosmetics, though there is potential for skin irritation¹²³.

Do the products meet the claims?

Now that we know the evidence, let’s look again at the de-waffled claims:

Some users report differences in the appearance of gray hair, but more research is needed.

I almost didn’t include this since it’s a bit hard to decipher – does a “difference in the appearance of gray hair” mean less grey hair, or that it’s still grey but looks different somehow, like softer or more glossy?

Ultimately I included it as a measure because any time you mention even a small chance of grey hair reversal in a product, it will fly off the shelves. People going grey really want to believe that something might work, and when coupled with the claim that you can’t expect to see benefits from a product for 4 months or more, it means you can make a lot of money from people before they realize it’s not working for them. A quick look at popular anti-grey companies tells you everything you need to know about this – they get terrible ratings on independent websites like TrustPilot¹²⁴ and Scam-Detector¹²⁵, but it’s all 5/5s on their own websites.

Having said that, I appreciate how careful Blueprint have been with their claim here, especially given the fact that at least 2 of the peptides have been shown to increase hair pigmentation so they could have made a bigger claim than they have here, and instead they are waiting.

Using the products for 6-9 months results in fuller, thicker looking strands and reduced dryness, flakiness and irritation.

These claims are all supported by evidence for some of the ingredients, however there are also some ingredients that cause those problems, so it’s hard to say what the ultimate outcome will be. Will the anti-inflammatory ingredients win against the inflammatory ones? That’s not clear to me.

I think what is clear is that some of the ingredients are odd choices and introduce unnecessary risk of irritation, so it will be interesting to see what people say about that when it has been in the wild for longer.

Both the Peptide Serum and Peptide Shampoo are free of drugs, hormones, SLS, parabens, gluten, sulfates, animal testing, carcinogens, and fragrance.

These claims are true with some caveats. While the Blueprint products in their final form may not have been tested on animals, most or all of the ingredients have been. There are also some fragrances, and while they’re not exactly carcinogens, some of the peptides have the risk of association with cancer, which leads onto the next claim:

Those with a history of skin cancer on the scalp should not use the products.

This suggests to me that the company knows about that association I just mentioned, so they are using very precise language when they say there are no carcinogens.

It’s good that they’re pointing this out, but it seems too important to be hidden away in a FAQ, it would be more responsible to disclose this on the product pages themselves.

So, should you buy them?

If you made it all the way to here, firstly you should be congratulated, and secondly, you probably want to know whether the potential benefits outweigh the potential costs.

Honestly, this is a hard one. Even in the longevity and healthspan space where it’s common to take on some degree of risk, introducing so many peptides in undisclosed amounts and in a relatively untested delivery mechanism is a lot to ask.

Some of the ingredients and peptides have big potential upsides, but are also entirely untested in this format, aside from any private testing that Blueprint has done which I don’t see any data on.

Not knowing the amounts of the peptides is also a problem because some serious side-effects have been found at higher doses, and we don’t know how close these formulations are to hitting those upper limits, and often we don’t even know what those upper limits would be, especially when liposomal and LLLT delivery are factored in.

While I was researching for this, which has taken me an entire month to do, Bryan mentioned that the products sold out immediately on launch¹²⁶, so it’s clear there is a lot of trust being placed in Bryan and Blueprint, and a lot of demand for products like these. I suspected that would be the case, which is why I didn’t take any shortcuts on this research. I wanted to do my best to enable people to make informed decisions about these products.

I would love to know what you think. Has this article changed your mind or made you more sure of your decision? Let me know, and don’t forget to subscribe for future reviews.

Updates

The following updates have been made to this article since it was published:

2025/10/05
Added reference to the Nature Aging review Sustained immune youth risks autoimmune disease in the aging host as example of not always wanting to match biomarkers with young people, in the Follistatin section.
2025/10/02
Removed mention of citric acid being a fragrance. There was a credible source for it, but then it contradicted itself later on, so I think it was in error. Thanks to Julie Forsey for the correction.