PT-141 (Bremelanotide) vs TB-500
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
PT-141 (Bremelanotide)
PT-141, also known as Bremelanotide, is a synthetic peptide analog of alpha-melanocyte-stimulating hormone. It is the only FDA-approved treatment for hypoactive sexual desire disorder (HSDD) in premenopausal women.
Full details →TB-500
Thymosin Beta-4 (TB-500) is a naturally occurring peptide present in almost all human and animal cells. It plays a crucial role in tissue repair and regeneration.
Full details →Side-by-Side Comparison
| Aspect | PT-141 (Bremelanotide) | TB-500 |
|---|---|---|
| Mechanism | PT-141 activates melanocortin receptors (MC3R and MC4R) in the central nervous system, particularly in areas associated with sexual arousal. Unlike PDE5 inhibitors, it works through the nervous system rather than the vascular system. | TB-500 promotes cell migration and differentiation, regulates actin (a cell-building protein), and reduces inflammation. It supports the formation of new blood vessels and wound healing. |
| Typical Dosage | FDA-approved dose: 1.75mg administered subcutaneously at least 45 minutes before anticipated sexual activity. Not to be used more than once within 24 hours or more than 8 times per month. | Research protocols typically use 2-2.5mg twice weekly during the loading phase, followed by maintenance dosing of 2mg every 2 weeks. |
| Administration | Subcutaneous injection in the abdomen. Available as Vyleesi (commercial product). Research use may involve different dosing protocols. | Administered via subcutaneous or intramuscular injection. Some protocols suggest injection near injury sites. |
| Side Effects | Common side effects include nausea (40% of users), flushing, headache, and injection site reactions. Transient blood pressure increases may occur. | May cause temporary fatigue, headache, or localized irritation at injection sites. |
| Best For |
What They Have in Common
Both PT-141 (Bremelanotide) and TB-500 are commonly used for: