In short
- Peptide and growth factor are not synonyms. They differ in size, in origin and in the evidence behind them. A label that mixes the two is not describing, it is selling.
- 🔑 The pooled evidence for growth factors exists and is modest: across 33 studies and 1,180 participants, a median improvement of under 50% in texture, under 35% in wrinkles and under 20% in overall appearance, as rated by the investigator.
- ⚠️ Only 9 of those 33 studies were randomised, 23 different preparations were used and the three comparative trials found no differences between treatments. It is a field with real results and weak methodology.
- 🚨 The obstacle is physical and comes before everything else. A peptide like acetyl hexapeptide-8 is hydrophilic and relatively large: its passage through the stratum corneum is limited, and whether it reaches a neuromuscular junction is still undemonstrated.
- 🚨 “Botox in a cream” cannot be true, and not as a matter of opinion. If a product genuinely had a pharmacological action on muscle, it would cease to be a cosmetic in law. The European Regulation prohibits attributing to a cosmetic functions it does not have.
- What it is reasonable to expect from this family is hydration, better texture and some perceived firmness, over months and with consistent use. It does not replace toxin, or filler, or surgery.
- 🔑 The price is not set by the active alone. It is set by stability, the delivery system, the packaging, the brand’s own trials — where they exist — and also by brand positioning. It is worth knowing which part you are paying for.
A peptide is a fragment of protein three to ten amino acids long. A growth factor is a complete protein, dozens of times larger, which in the body acts as a messenger between cells. They are two different families, with two different mechanisms and two different levels of evidence, even though advertising presents them as one. What they do share is an obstacle that comes before any discussion of efficacy: they are large, water-loving molecules, and they have to cross the stratum corneum, which is designed to prevent exactly that.
For growth factors there is a pooled measurement. A 2023 systematic review brought together 33 studies and 1,180 participants, and the result is neither zero nor spectacular: a modest improvement, greater in texture than in wrinkles, and greater when it is the user doing the rating than when the investigator measures it. This page sets out what there is, what there is not, and what part of the price corresponds to each.
It is the most expensive end of dermocosmetics, and therefore the one that most deserves a calm look before buying.
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Two families marketing joins and biology separates
The peptides
A peptide is a short chain of amino acids. Three types are mainly used in skincare, with different logics:
- Signalling peptides. The idea is to mimic the fragments that appear when collagen breaks down, and which the tissue itself reads as an order to make more matrix. The best known is palmitoyl pentapeptide and its combinations.
- Peptides that act on the nerve signal, at least in the test tube. Acetyl hexapeptide-8 and dipeptide diaminobutyroyl benzylamide diacetate — the one the industry calls Syn-Ake — belong to this group. It is the family advertising christened “botox in a cream”, and below is why that label does not hold up.
- Carrier peptides, typically of copper, whose stated function is to transport an ion with a role in wound healing.
The growth factors
They are complete proteins — EGF, TGF-β, VEGF, IGF and others — that cells use to talk to each other: to divide, to migrate, to make matrix. In a cosmetic they can come from three very different origins:
- Recombinant human, produced by biotechnology. In an ingredients list they are recognised because they are declared as
sh-Oligopeptide-1,sh-Polypeptide-...and names of that form. - From cell culture medium, including those derived from stem cell cultures.
- Of plant origin — so-called meristematic cell cultures. 🔑 These are not equivalent to the human ones: a plant does not make human EGF. They share a trade name, not a molecule.
⚠️ The practical consequence is that two bottles advertising “growth factors” can contain very different things. And also that a product can carry the whole family in its name without the main active being a growth factor at all. The only way to know is to read the ingredients list, which by law has to be on the pack.
What the evidence for growth factors measures
Here there is a pooled answer, and it is worth reading in full before drawing conclusions in either direction.
A systematic review published in 2023 in the Journal of Cosmetic Dermatology searched four databases for prospective trials and case series of at least ten participants, between 2000 and October 2022. It gathered 33 studies, 1,180 participants and 23 different topical preparations. In almost all of them the product was applied twice a day, with a mean treatment duration of three months.
The results, as rated by the investigator:
| What was measured | Improvement (median) |
|---|---|
| Skin texture | less than 50% |
| Fine lines and wrinkles | less than 35% |
| Overall facial appearance | less than 20% |
And three qualifications the review itself states, which change how that table has to be read:
- The improvement the participant perceived was generally greater than the one the investigator measured. It is a known pattern in skincare and does not invalidate the result, but it explains why user experience and data do not always coincide.
- Only 9 of the 33 studies were randomised trials; the remaining 24 were uncontrolled case series. Nine used placebo or an active control.
- The three comparative trials found no statistically significant differences between the treatments they set against each other.
The review also concludes that the risk of adverse effects is low, and that the heterogeneity — in the source of the factors, in their number and in how the result was measured — makes a single figure impossible.
🔑 Translated: there is a signal, it is small, and it does not allow anyone to say one preparation is better than another. Any page that puts a round percentage on this is making it up.
The problem that comes before efficacy: size
Before asking whether an active works it is worth asking whether it gets there. The stratum corneum is a lipid barrier whose function is to prevent the passage of large, water-loving molecules. Peptides and growth factors are exactly that.
A 2025 review focused on acetyl hexapeptide-8 puts it plainly: because of its hydrophilic nature and relatively large molecular size, its permeability through the lipophilic stratum corneum is limited, and getting it to the dermis is a formulation problem. Oil-in-water emulsions and multiple water-in-oil-in-water emulsions have been tried to improve that delivery, but — and this is verbatim in the review — the peptide’s ability to reach the neuromuscular junctions remains uncertain.
⚠️ That does not mean the product does nothing. The studies gathered in that same review describe reduced wrinkle depth and better elasticity and hydration. It means the mechanism by which it does so is probably not the one the label advertises, and that part of the result may come from the vehicle — from the fact of moisturising dry skin well — rather than from the peptide.
🔑 A practical rule that holds for this whole family: the larger and more hydrophilic the molecule, the more the formulation weighs and the less the name of the active does. That is why two products with the same peptide on the label can behave very differently.
“Botox in a cream”: why that phrase cannot be true
It is the sector’s most repeated expression and it is worth taking apart precisely, because the problem is not one of efficacy but of category.
Article 20.1 of Regulation (EC) 1223/2009 says that in the labelling, marketing and advertising of cosmetic products text, names, trade marks, pictures or any other sign shall not be used to imply that these products have characteristics or functions which they do not have. On that article were built the common criteria of Regulation 655/2013, which require every claim to be truthful, honest, supported by evidence and not misleading.
And there is a second, prior boundary: a product exerting a real pharmacological action on the neuromuscular junction would not be a cosmetic. It would be a medicine, with its dossier, its authorisation and its prescription. Botulinum toxin is one: it is injected, administered by a doctor and has a summary of product characteristics. A peptide applied to the skin cannot claim that effect and go on being sold in a cosmetics bottle.
⚠️ What the literature does debate is whether a topical peptide can produce some softening of a dynamic wrinkle by indirect routes. There is a 2025 review in the Journal of Drugs in Dermatology that addresses precisely that question — acetyl hexapeptide-8 as a topical alternative to toxin — and the fact that the question is still open and under review is itself the answer: there is no demonstrated equivalence.
🔑 How to read it in practice: “immediate tightening effect” is a claim about how the skin feels and can be true. “Botox effect” is a claim about muscle, and it is not.
Why they cost what they cost
It is the question people ask in the consulting room and almost nobody answers. The price of a serum in this family is split, in widely varying proportions, between:
- Stability. A peptide or a protein degrades. Keeping them intact calls for preservatives, pH control and sometimes an airless pump with no air return. That costs money and does not show.
- Delivery system. Encapsulation, liposomes, multiple emulsions. It is where the efficacy of a large molecule is really decided, and it is expensive.
- The brand’s own trials. Some brands fund studies of their specific formulations. Others rely on the literature for the ingredient. The difference in cost is enormous, and so is the difference in evidence.
- Concentration and quality of the raw material. A cosmetic-grade synthetic peptide has a very high price per gram.
- Brand, distribution and channel. Part of the price is positioning. It is not illegitimate, but it is worth knowing it is there.
⚠️ What the price does not guarantee is the size of the effect. The three comparative trials in the 2023 review found no differences between the treatments they set against each other. A more expensive product may be better formulated, better preserved and more pleasant to use — things that matter, because they determine whether it is used daily or abandoned — without that translating into one wrinkle fewer.
A specific warning that comes out of reading labels
🚨 In this segment it is common for a product to contain a retinoid without being sold as a retinol product. Retinol and its esters — retinyl palmitate, retinaldehyde — appear in “firming”, “night” or “daily defence” formulations whose name does not suggest it.
The consequence is real: someone using a retinol treatment at night and adding a serum from this family may be stacking two retinoids without knowing it, which is precisely the cause of irritation explained in how to start with retinol. It takes thirty seconds to check by reading the pack’s ingredients list and looking for the words Retinol, Retinyl Palmitate or Retinaldehyde. If you have doubts about what you already use, it is one of the things we go through in the consulting room with the packs in front of us.
What it is reasonable to expect, and over what time
- Months, not weeks. The mean treatment duration in the reviewed studies was three months, and that is the minimum period for judging.
- Texture before wrinkles. It is what the medians show: texture improves more than a set line does.
- Consistency over potency. Just as with retinol, what separates a result from no result is sustained use.
- With sun protection, or it does not count. No repair active competes with damage that keeps accumulating every morning. It is set out in how to choose a sunscreen.
- 🚨 And one expectation that has to be lowered explicitly: no cosmetic in this family lifts sagging tissue, repositions an eye bag or replaces a filler. That is laxity, and laxity is a problem of structure, not of surface.
When a peptide is not the answer
It is worth saying even though it works against the sale, because it is what separates a recommendation from a sales pitch.
- If what bothers you is an expression line set at rest, a cosmetic is not the tool. The real option is in treatment with botulinum toxin, assessed in the consulting room.
- If what bothers you is loss of volume or support, no again. There the conversation is about injected hyaluronic acid or surgery, depending on the case.
- If what bothers you is the quality of the skin overall — texture, pores, radiance — there are alternatives with more mileage than a serum: chemical peel, CO₂ laser or facial redensification.
- If there is pigmentation, the order of priorities is different and it is in creams for facial pigmentation.
🔑 A peptide serum makes sense as maintenance and as a complement, not as a substitute for a treatment that corrects something else.
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Frequently asked questions
Do peptides really work?
It depends what you mean by work. There are studies describing improvement in hydration, elasticity and wrinkle depth with topical peptides. What is not demonstrated is the mechanism advertising attributes to them, and specifically that they reach the neuromuscular junction. It is reasonable to expect a modest improvement in the quality of the skin, not an effect on muscle.
Is a plant growth factor the same as a human one?
No. A plant does not make human growth factors. Extracts of plant cell cultures are something else, with different evidence, and sharing a trade name does not make them equivalent. They can be told apart in the ingredients list: the recombinant human ones are declared as sh-Oligopeptide or sh-Polypeptide, and the plant ones as meristematic cell cultures of a specific species.
Can a cosmetic relax muscle the way botulinum toxin does?
No, and it is not a matter of potency but of legal category. A product with a pharmacological action on muscle would be a medicine, not a cosmetic. The European Regulation expressly prohibits attributing to a cosmetic functions it does not have. The phrase “botox in a cream” describes an expectation, not a mechanism.
Is a €200 serum worth it?
It may be if that formulation is the one you manage to use daily for months, because consistency weighs more than the label. It is not if it is bought expecting a result from a medical consultation. And it is worth knowing that in the available comparative trials no significant differences were found between products: price does not predict the size of the effect.
Can peptides be combined with retinol or vitamin C?
Generally yes, and in fact many formulations contain them together. The caution is not about chemical incompatibility but about accumulated irritation: if several actives are started in the same week, the skin protests and you do not know which one it was. You introduce one at a time. And it is worth checking whether the serum itself already contains a retinoid, because then you are not combining: you are doubling up.
Do they have to be stopped before surgery or a laser?
It is a decision taken in the consulting room, with the product in front of you, and it depends above all on whether the formulation contains a retinoid or an acid as well as the peptide. The general criterion is in skincare before and after surgery.
Do they work for dark circles and the eye area?
It is one of the areas where they are sold most and where it matters most to be clear about what is being treated. It is set out in eye creams.
Sources
- Quinlan A, et al. Topical growth factor preparations for facial skin rejuvenation: A systematic review. Journal of Cosmetic Dermatology, 2023. PMID 37222303. — A search of the Cochrane Library, EMBASE, MEDLINE and Scopus from 2000 to October 2022, limited to prospective trials and case series with ten or more participants. 33 studies, 9 of them randomised, 1,180 participants and 23 different preparations. Applied twice daily except in two studies; mean treatment duration, three months. Improvement rated by the investigator: texture median < 50%, fine lines and wrinkles median < 35%, overall facial appearance median < 20%. The improvement reported by the participant was generally greater than the one rated by the investigator. Three randomised comparative trials showed no statistically significant differences between treatments. The authors note heterogeneity in the source and number of factors and a lack of standardisation of the measures, and a low risk of adverse effects.
- Acetyl Hexapeptide-8 in Cosmeceuticals — A Review of Skin Permeability and Efficacy. International Journal of Molecular Sciences, 2025. PMID 40565185. — A review focused on the skin permeability of acetyl hexapeptide-8, the peptide the industry calls “botox-like”. It states that because of its hydrophilic nature and relatively large molecular size, permeability through the lipophilic stratum corneum is limited, that O/W and W/O/W emulsions have been explored to improve dermal delivery, and that the peptide’s ability to reach the neuromuscular junctions remains uncertain. The preclinical and clinical studies gathered describe reduced wrinkle depth and better elasticity and hydration, without the precise biological mechanisms being established.
- Acetyl Hexapeptide-8 as a Topical Alternative to Botulinum Toxin: A Review of the Literature. Journal of Drugs in Dermatology, 2025. PMID 40196949. — A review of the literature on the use of acetyl hexapeptide-8 as a topical alternative to botulinum toxin. It is cited as evidence that equivalence remains a matter under review and not an established fact.
- Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products — article 20, “Product claims”. Consolidated text on EUR-Lex. — Paragraph 1, verbatim: “In the labelling, making available on the market and advertising of cosmetic products, text, names, trade marks, pictures and figurative or other signs shall not be used to imply that these products have characteristics or functions which they do not have.” Verified against the consolidated text on 28-08-2026.
- Commission Regulation (EU) No 655/2013 laying down common criteria for the justification of claims used in relation to cosmetic products. EUR-Lex. — It sets the six common criteria: legal compliance, truthfulness, evidential support, honesty, fairness and informed decision-making.
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If you are considering a product in this segment — or you already have several at home and do not know whether they overlap — the most useful thing is not comparing prices: it is reading the ingredients lists together and deciding what is needed and what is surplus. It is part of the skin quality assessment in the consulting room, and the result is often a shorter routine. You can see the products we work with in our peptides and advanced anti-ageing shop, though the choice is best made on reasoning rather than on a label.
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Last reviewed: 20 September 2026. This content is for information only and does not replace an individual assessment by a healthcare professional.
