Peptides A to Z
This library covers the peptides people in Lakeland and Polk County most often ask about, grouped by what they are used or marketed for. Every page follows the same layout, so you can compare them easily:
- At a glance: the type of peptide, how strong the human evidence is, and its FDA status with the date we last checked it.
- What it is and how it works, in plain language.
- What the research shows, including where evidence is weak or missing.
- FDA and regulatory status, dated, because rules on peptides and compounding change often.
- Side effects and safety, cost, and questions to ask a provider.
Facts on each page are numbered and linked to their sources, such as FDA documents, drug labels and published studies, in a References list at the bottom. These pages summarize what those public sources say. They are not our own conclusions, and they are not medical advice. Consult a licensed health care provider before you decide anything.
The peptides here vary a lot in how well they have been studied. Some, like semaglutide and tirzepatide, have been tested in large human trials and are part of FDA-approved medicines. Others, like BPC-157, are popular online but have little or no human research behind them. The colored evidence label on each peptide shows that difference at a glance.
If you are not sure which peptide to read about, start with your goal instead. Before you talk to a clinic, it also helps to read about compounded versus FDA-approved products and the risks of research chemical peptides.
These pages are general education, not medical advice. Talk to a licensed provider about your own situation.
How to read the evidence labels
- FDA-approved Approved by the FDA for specific uses after large clinical trials.
- Some human trials Studied in people, but not FDA-approved for the uses it is marketed for.
- Very limited human data Only small or early human studies exist.
- Animal and lab data only No meaningful published human trials.
Weight and metabolism
Incretin medicines (GLP-1 and related) and other peptides studied for body weight and metabolic health.
- AOD-9604Some human trialsA lab-made piece of growth hormone first developed for weight loss. Its largest trial failed, FDA found no good evidence it works, and injected forms were never tested in people.
- LiraglutideFDA-approvedAn older, once-daily GLP-1 medicine sold as Victoza and Saxenda, now also as FDA-approved generics. Trials show modest weight loss and fewer heart events in type 2 diabetes.
- MOTS-cAnimal and lab data onlyA small peptide made by the body's mitochondria. Mouse studies are interesting, but no study has given MOTS-c to people, so FDA says its benefits and risks in humans are unknown.
- RetatrutideSome human trialsAn experimental weekly shot that acts on three hormone receptors. Large 2026 trials showed major weight loss, but it is not FDA-approved, and 'research use only' versions sold online are not legal medicines.
- SemaglutideFDA-approvedAn FDA-approved GLP-1 medicine sold as Ozempic, Rybelsus and Wegovy. Large trials show weight loss and fewer heart events, but weight tends to return after stopping.
- SS-31 (elamipretide)FDA-approvedA small peptide that targets mitochondria. FDA approved it in 2025, as Forzinity, only for one very rare inherited disease. It is a specialty drug, not a proven energy or anti-aging product.
- TirzepatideFDA-approvedAn FDA-approved weekly shot sold as Zepbound and Mounjaro that acts on two gut-hormone receptors. Large trials show sizable weight loss, but weight tends to return after stopping.
Growth hormone–related peptides
Peptides that act on the body’s growth hormone system, either like GHRH or like ghrelin.
- CJC-1295Very limited human dataA lab-made analog of a brain hormone that signals the pituitary to release growth hormone. It has never been FDA-approved, FDA lists safety concerns, and published human research is limited.
- GHRP-2Some human trialsA lab-made peptide that copies the hunger hormone ghrelin and prompts a growth hormone pulse. Japan approved it only as a diagnostic test. As a treatment in children, it did not improve growth.
- GHRP-6Very limited human dataThe original ghrelin-copying peptide. It reliably raises growth hormone, but also cortisol and hunger, and no controlled trial has tested it for any treatment goal.
- IpamorelinVery limited human dataA lab-made peptide that prompts the pituitary to release a pulse of growth hormone. It is not FDA-approved, only two human studies were published, and its one efficacy trial did not work.
- SermorelinSome human trialsA lab-made piece of a natural brain hormone that prompts the pituitary to release growth hormone. Once approved only for children, it was discontinued in 2008. Adult studies are tiny and short.
- TesamorelinFDA-approvedAn FDA-approved GHRH analog labeled only for excess belly fat in adults with HIV-related lipodystrophy. It reduced deep belly fat in trials but not body weight, and the fat returned after stopping.
Tissue repair and recovery
Peptides marketed for injury recovery. Most of the evidence comes from animal studies.
- BPC-157Very limited human dataA lab-made peptide studied mostly in rats for healing. Human data are a handful of tiny studies, none using the forms clinics sell. It is not FDA-approved, and a 2026 HHS compounding policy is only a draft.
- TB-500Animal and lab data onlyA lab-made, 7-amino-acid piece of thymosin beta-4, first sold for racehorses. It has never been tested in a published human study. It is not FDA-approved, and a 2026 HHS compounding policy is only a draft.
Skin and immune peptides
Peptides studied for skin, wound healing, inflammation and immune function.
- GHK-CuVery limited human dataA small copper-binding peptide the body makes, and a common skin-cream ingredient. Human studies are few, small and mostly cosmetic. Injections have never been tested in trials, and it is not an FDA-approved drug.
- KPVAnimal and lab data onlyA three-amino-acid piece of a natural hormone that calmed gut inflammation in mice. FDA found no human studies at all. It is not FDA-approved, and a 2026 HHS compounding policy is only a draft.
- LL-37Very limited human dataAn infection-fighting peptide the body makes. A topical version looked promising for leg ulcers in a tiny trial but failed in a larger one. It has not been tested as an injection, and FDA has raised safety concerns.
- Thymosin alpha-1Some human trialsAn immune-signaling peptide from the thymus, sold as Zadaxin outside the U.S. It is not FDA-approved. The largest trials, in sepsis and hepatitis B, did not show a clear benefit on their main goals.
Sexual and reproductive health
Melanocortin and reproductive-hormone peptides, from FDA-approved medicines to unapproved products.
- KisspeptinSome human trialsKisspeptin is a natural hormone that starts the signals behind ovulation and sperm production. Small studies in IVF and low desire look promising, but it is experimental and not FDA-approved.
- Melanotan IIVery limited human dataMelanotan II is a lab-made version of a skin-darkening hormone. It was never approved and is sold online for tanning. Case reports describe mole changes, melanoma and prolonged erections.
- OxytocinFDA-approvedOxytocin is a natural hormone. It is FDA-approved only as a hospital injection used during and after childbirth. Nasal sprays are promoted for trust and sex, but the research is mixed or negative.
- PT-141FDA-approvedBremelanotide (PT-141) is FDA-approved as Vyleesi only for premenopausal women with a specific low-desire diagnosis. Trials showed modest gains over placebo, and nausea is common.
Longevity, mitochondrial and cognitive peptides
Peptides marketed for aging, energy or brain function. Human evidence is mostly limited.
- EpitalonVery limited human dataEpitalon is a four-amino-acid peptide from one Russian research group, promoted for anti-aging. Lab studies suggest telomere effects, but no good human trials show it slows aging, and FDA found no safety studies.
- SelankVery limited human dataSelank is a lab-made peptide sold in Russia as anti-anxiety nose drops. A few small Russian studies compared it with sedatives, but none used a placebo. It is not FDA-approved.
- SemaxVery limited human dataSemax is a lab-made peptide based on part of the hormone ACTH, sold in Russia as nose drops. FDA found insufficient evidence it works for the uses it reviewed, and it is not FDA-approved.
Frequently asked questions
Are all peptides on this site FDA-approved?
No. Some, like semaglutide and tirzepatide, are active ingredients in FDA-approved prescription medicines. Many others have not been approved for any use in people. Each page shows the FDA status and the date we last checked it.
Where does the information on these pages come from?
Each fact is linked to a numbered source in the References list at the bottom of the page. We rely on FDA documents, drug labels, clinical trials and systematic reviews, not on clinic or seller marketing.
Which peptide is best?
There is no single best peptide. The right choice, if any, depends on your goal, health history and other medicines. A licensed provider can help you weigh the options.
Questions? Talk to a licensed provider
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