New to peptides? Start here

What people mean by "peptides"

The word covers very different products, and the sections below take them one at a time:

• creams and serums you put on the skin
• collagen supplements you take by mouth
• prescription medicines
• injectables bought online

Cosmetic, prescription or unauthorized: who checks what

Under the FD&C Act, cosmetic products and ingredients, with the exception of color additives, do not require FDA approval before they go on the market; the Act defines drugs, in part, by their intended use, including “articles (other than food) intended to affect the structure or any function of the body of man or other animals”, and some products meet the definitions of both cosmetics and drugs. ^[4]

Semaglutide, tirzepatide and orforglipron are approved prescription drugs, and their labels say which symptoms mean calling a prescriber ^{[5] [6] [7]}.

Health Canada lists BPC-157, TB-500, KPV and GHK-Cu among unauthorized injectable peptides it has seized, and says such products are often promoted online, including for injury recovery and athletic performance ^[3].

• Regulator document Health Canada warns that unauthorized peptide drugs may lead to infections, allergic reactions and other serious complications; may contain too much, too little or none of the active ingredient; may contain contaminants such as particles, bacteria, fungi or endotoxins; and may be poorly labelled or improperly stored.^[3]
• Expert review A 2026 review says unapproved peptides sold without a prescription, such as BPC-157, TB-500 and melanotan-II, lack established human safety profiles, and that their use brings potential risks including product contamination and manufacturing impurities.^[8]

What has been tested in people, for looks

A high tier means more human evidence exists for some outcome. It never means a better face. The strongest results we cite are below; each topic has its own page under "Where to go next".

• Expert review A 2026 meta-analysis of 19 randomized trials of oral and topical peptides found a modest pooled wrinkle effect, largely driven by oral polypeptides. Effects on elasticity and density were inconsistent.^[9]
• Human RCT In a 12-week split-face trial of 93 women aged 35–55, pal-KTTKS (palmitoyl pentapeptide) reduced fine lines more than the same moisturizer without peptide.^[1]
• Expert review A 2025 review notes a "surprising absence of clinical studies" of topical GHK-Cu, and a 2026 systematic review calls the human evidence thin.^[10][11]
• Expert review Pooled trials report better skin hydration and elasticity with oral collagen.^[12][13]
• Expert review A 2025 meta-analysis of 23 collagen trials found no skin benefit in trials without pharmaceutical-company funding or in high-quality trials.^[14]
• No supporting study We found no peptide product with placebo-controlled evidence comparable to the trials behind minoxidil and finasteride, and a 2025 review says most studies of these topical actives were small.^[15][16]
• No supporting study We found no published study of the GLOW or KLOW blends in people, animals or cells. For one of their ingredients, TB-500, FDA found no human exposure data.^[17]

How to judge a peptide claim

On the topic pages, each cited claim carries a grade for the strongest kind of evidence behind it; how we grade evidence explains every grade. Before you believe a claim anywhere, ask:

• Was it tested in people, or only in cells or animals?
• How many people, for how long, and compared with what?
• Was the product tested the same as the one being sold, or part of a blend?
• Who paid for the research?

In FDA's 2026 review of BPC-157, the certificates of analysis submitted listed purity but no results for specified impurities, aggregates, microbial load or bacterial endotoxins, and FDA's literature search found that most such certificates report purity alone ^[18].

Two lab studies in our checked reference set tested peptide products sold outside pharmacies against what the sellers claimed or the labels stated ^{[19] [20]}. Both tested small numbers of products, so they show that mislabeling happens, not how often.

See how to read a certificate of analysis for what product testing can and cannot show.

• Regulator document A certificate is not an approval. FDA says compounded drugs are not FDA approved, so it does not review them for safety, effectiveness or quality before they are marketed, and for BPC-157 it says it lacks sufficient information to know whether the drug would cause harm in people.^[21][22]

Warning signs

Health Canada advises anyone who feels unwell after using an unauthorized injectable peptide drug to talk to a healthcare professional right away, and the GLP-1 drug labels name the symptoms that mean stopping the medicine and getting help, such as severe stomach pain that will not go away or swelling of the face and throat ^{[3] [5] [6]}.

See peptide red flags for every sign named in the sources, and what to tell a clinician. Questions to take to a doctor are further down this page.

Where to go next

• Skin: best peptides for skin, ranked by evidence, then copper peptides vs retinol.
• Hair: peptides for hair growth vs minoxidil and finasteride.
• Face shape and the jaw: peptides for looksmaxxing and the jawline myth-check.
• Oral collagen: what the collagen trials show.
• Only if a prescriber has already given you a dose: the reconstitution calculator does the math on numbers you type, with no dose or compound presets.
• Measure, then track: after a free SoftMaxx AI scan, the Protocol tab of your results has a routine log, and what you enter in it stays on your device.

Coming soon for Pro members: the Personal Evidence Plan

We are building a Personal Evidence Plan for Pro members. It will bring together:

• your measured baseline from your own scan
• the options for the concern you pick, ranked by how much human evidence exists
• questions to take to your doctor
• a rescan schedule, so you compare like with like

What it will not do:

• It will not give doses.
• It will not choose a compound for you.
• It will not name, link or recommend sellers.

It is not available yet.

Report a side effect

Questions to ask your doctor

SoftMaxx AI gives no doses or prescriptions; take these to a clinician.

• Is this product a cosmetic, a prescription medicine, or neither?
• Is there an approved option for what I want to change, and how strong is its evidence?
• Could the product interact with my other medicines or supplements?
• What should I watch for, and when should I stop and call you?
• How long should I give it before we judge whether it changed anything?

Common questions

References

References to papers were matched to their PubMed or DOI records. Regulator, label and registry pages were fetched and saved by us. "Verified" means the paper exists and is the one named; what it supports is stated next to each claim.

1. Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin. Int J Cosmet Sci (2005). PubMed 18492182 DOI
2. The anti-wrinkle efficacy of argireline, a synthetic hexapeptide, in Chinese subjects: a randomized, placebo-controlled study. Am J Clin Dermatol (2013). PubMed 23417317 DOI
3. Think twice before injecting peptides bought online: unauthorized products can seriously harm you (Health Canada advisory; lists KPV) Recalls and safety alerts, Government of Canada (2026). Source
4. Is It a Cosmetic, a Drug, or Both? (Or Is It Soap?) fda.gov. Source
5. WEGOVY (semaglutide) injection; WEGOVY (semaglutide) tablets — Prescribing Information DailyMed (2026). Source
6. ZEPBOUND (tirzepatide) injection — Prescribing Information DailyMed (2026). Source
7. FOUNDAYO (orforglipron) tablets — Prescribing Information DailyMed (2026). Source
8. Dangers of Injectable Peptides and Other Unregulated "Biohacking" Drugs. Mo Med (2026). PubMed 42757290
9. Oral and topical peptides for skin aging: systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne) (2026). PubMed 41924746 DOI
10. Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective. Bioimpacts (2025). PubMed 39963574 DOI
11. A Systematic Review of the Mechanisms and Therapeutic Applications of GHK-Cu (Glycyl-L-Histidyl-L-Lysine-Copper Complex) in Topical Microneedle Delivery: A Case for Expanded Clinical Trials. Arch Intern Med Res (2026). PubMed 42787770 DOI
12. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. Int J Dermatol (2021). PubMed 33742704 DOI
13. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients (2023). PubMed 37432180 DOI
14. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am J Med (2025). PubMed 40324552 DOI
15. The effectiveness of treatments for androgenetic alopecia: A systematic review and meta-analysis. J Am Acad Dermatol (2017). PubMed 28396101 DOI
16. Topical Alternatives for Hair Loss: Beyond the Conventional. Int J Trichology (2025). PubMed 40654553 DOI
17. July 23-24, 2026, Meeting of the Pharmacy Compounding Advisory Committee – FDA Briefing Document for TB-500-Related Bulk Drug Substances (TB-500 (free base) and TB-500 acetate) (2026). Source
18. July 23-24, 2026, Meeting of the Pharmacy Compounding Advisory Committee – FDA Briefing Document for BPC-157-Related Bulk Drug Substances (BPC-157 (free base) and BPC-157 acetate) (2026). Source
19. Identification and characterization by LC-UV-MS/MS of melanotan II skin-tanning products sold illegally on the Internet. Drug Test Anal (2015). PubMed 24771717 DOI
20. Detection of black market follistatin 344. Drug testing and analysis (2019). PubMed 31758732 DOI
21. FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss fda.gov (2026). Source
22. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks fda.gov (2026). Source
23. An Herbal Extract Combination (Biochanin A, Acetyl tetrapeptide-3, and Ginseng Extracts) versus 3% Minoxidil Solution for the Treatment of Androgenetic Alopecia: A 24-week, Prospective, Randomized, Triple-blind, Controlled Trial. J Clin Aesthet Dermatol (2020). PubMed 33584955
24. The effect of tripeptide-copper complex on human hair growth in vitro. Arch Pharm Res (2007). PubMed 17703734 DOI