Weight Loss & Metabolic Health
| Peptide | Commonly Used/Studied For |
|---|---|
| Semaglutide | Weight loss, appetite reduction, blood-sugar control; GLP-1 agonist |
| Tirzepatide | Weight loss and type 2 diabetes; GLP-1/GIP agonist |
| Retatrutide | Investigational weight loss/metabolic therapy; GLP-1/GIP/glucagon triple agonist |
| Cagrilintide | Investigational appetite suppression and weight loss; long-acting amylin analog |
| MOTS-c | Experimental mitochondrial/metabolic peptide; studied for glucose metabolism, insulin sensitivity and exercise physiology |
Growth Hormone / Body Composition
| Peptide | Commonly Used/Studied For |
|---|---|
| Tesamorelin | Stimulates growth hormone; FDA-approved to reduce excess abdominal fat in adults with HIV-associated lipodystrophy |
| Sermorelin | Growth-hormone stimulation; commonly marketed in longevity/anti-aging settings |
| CJC-1295 | Experimental growth-hormone-releasing hormone analog |
| Ipamorelin | Experimental growth-hormone secretagogue |
| GHRP-2 | Experimental growth-hormone stimulation |
| GHRP-6 | Experimental GH stimulation; can also substantially increase appetite |
| Hexarelin | Potent experimental GH secretagogue |
Injury, Tissue & Gut Research
| Peptide | Commonly Used/Studied For |
|---|---|
| BPC-157 | Experimental tendon, ligament, muscle, gastrointestinal and wound-healing research |
| TB-500 / thymosin-β4-related products | Experimental tissue repair, inflammation and recovery |
| KPV | Experimental anti-inflammatory and gastrointestinal research |
| GHK-Cu | Skin remodeling, wound healing, collagen and hair research; widely used in topical cosmetic products |
| ARA-290 / cibinetide | Investigational tissue-protective and anti-inflammatory compound; studied particularly in neuropathic conditions |
Mitochondria, Energy & Longevity Research
| Peptide | Commonly Used/Studied For |
|---|---|
| SS-31 / Elamipretide | Investigational mitochondrial-targeting peptide; studied for mitochondrial function and cellular energy |
| MOTS-c | Mitochondrial signaling, metabolic function, glucose regulation and exercise physiology |
| Humanin | Experimental mitochondrial-derived peptide studied in cellular stress, metabolism and aging biology |
| Epitalon | Experimental longevity/aging research; often associated with telomere research, but human evidence is limited |
Immune & Inflammation
| Peptide | Commonly Used/Studied For |
|---|---|
| Thymosin Alpha-1 (TA-1) | Immune-system modulation; approved for certain indications in some countries, but not FDA-approved in the U.S. |
| KPV | Experimental anti-inflammatory research, particularly involving the gut and skin |
| LL-37 | Naturally occurring antimicrobial peptide studied in innate immunity and wound biology |
Brain, Focus, Anxiety & Sleep
| Peptide | Commonly Used/Studied For |
|---|---|
| Semax | Experimental cognitive, attention and neuroprotective research; used medically in some countries but not FDA-approved |
| Selank | Experimental anxiety, stress and cognitive research |
| DSIP | Experimental sleep/stress research; evidence remains limited |
Sexual & Reproductive Health
| Peptide | Commonly Used/Studied For |
|---|---|
| PT-141 / Bremelanotide | Sexual desire/arousal; bremelanotide is FDA-approved for acquired, generalized HSDD in certain premenopausal women |
| Kisspeptin | Reproductive-hormone signaling, fertility and hypothalamic-pituitary-gonadal-axis research |
| Oxytocin | Hormone/peptide involved in childbirth, lactation and social behavior; approved medical formulations have specific obstetric uses |
Skin, Hair & Cosmetic Applications
| Peptide | Commonly Used/Studied For |
|---|---|
| GHK-Cu | Collagen, skin quality, wound healing and hair-growth research |
| Matrixyl peptides | Cosmetic anti-aging products aimed at improving appearance of wrinkles and skin |
| Argireline | Cosmetic peptide marketed for reducing the appearance of expression lines |
| SNAP-8 | Cosmetic peptide used in anti-wrinkle formulations |
Other Frequently Discussed Experimental Peptides
| Peptide | Area of Interest |
|---|---|
| FOXO4-DRI | Experimental senescent-cell research; largely preclinical |
| Cartalax | Marketed for cartilage/joint and aging applications; robust clinical evidence is limited |
| Vesugen | Marketed for vascular support/aging; clinical evidence is limited |
| VIP (vasoactive intestinal peptide) | Naturally occurring signaling peptide involved in vasodilation, pulmonary, gastrointestinal and immune physiology |
| Melanotan II | Experimental pigmentation/tanning and sexual-function effects; not FDA-approved |
A Simple Way to Think About Them
The major categories are:
Metabolic: Semaglutide, Tirzepatide, Retatrutide, Cagrilintide, MOTS-c
Growth hormone/body composition: Tesamorelin, CJC-1295, Ipamorelin, Sermorelin
Healing/recovery: BPC-157, TB-500, KPV, GHK-Cu
Mitochondrial/longevity: SS-31, MOTS-c, Humanin, Epitalon
Immune/inflammation: TA-1, KPV, LL-37
Brain/cognition: Semax, Selank, DSIP
Sexual/reproductive: PT-141, Kisspeptin, Oxytocin
Skin/cosmetic: GHK-Cu, Matrixyl, Argireline, SNAP-8
Important Distinction
These compounds aren’t all on the same scientific footing. Some—such as semaglutide, tirzepatide, tesamorelin and bremelanotide—have FDA-approved pharmaceutical uses. Others, including BPC-157, MOTS-c, SS-31/elamipretide, CJC-1295, ipamorelin and retatrutide, are investigational or lack FDA approval for routine clinical use.
For educational material, it’s therefore better to say a compound is “being studied for” something rather than saying it “treats” that condition unless the indication is actually established and approved.
MEDICAL DISCLAIMER: I am not a doctor, and nothing on this site or in this book is medical advice. Timeless Aging is a personal account and an educational resource. It is not intended to diagnose, treat, cure or prevent any disease. Peptides and other compounds discussed may be regulated, may require a prescription, and may not be legal to obtain or use in your jurisdiction. Talk to a qualified, licensed physician before changing your diet, starting an exercise program, or taking any supplement or compound — especially if you are pregnant, nursing, under 18, taking medication, or living with any medical condition.