Prostaglandin F2-alpha, not a peptide
PGF-2α
Label Veterinary / ophthalmic use
What it is
PGF-2α (dinoprost) is a prostaglandin, a small lipid signaling molecule derived from arachidonic acid — chemically unrelated to peptides. It is FDA-approved in ophthalmic form for lowering intraocular pressure and is used in veterinary medicine to synchronize estrus in livestock. It is included because it circulates in bodybuilding discussion as a supposed localized muscle agent.
Benefits in plain language
What researchers and reference users usually mean when they talk about this compound. These are study themes and common claims — not a promise that it will do this in you.
- This is not a peptide at all — it is a lipid hormone your body makes as part of inflammation and uterine signaling.
- The bodybuilding story is local muscle growth after site injection. That is a forum claim, not a validated effect.
- Its real medical uses are eye pressure and, in animals, reproductive timing.
- Site-injection claims ignore that this compound is a potent smooth-muscle and vascular agent.
If a branded, FDA-approved product exists, that label is the only dose that is actually authorized. Research-chemical vials are a different object.
Mechanism of action
PGF-2α binds the FP receptor, a Gq-coupled receptor that raises intracellular calcium and drives smooth-muscle contraction. In the eye it increases uveoscleral outflow to lower pressure. In reproductive tissue it drives luteolysis. Any effect on skeletal muscle protein synthesis is indirect at best and not an established therapeutic mechanism.
Possible side effects / caveats
Systemic exposure causes bronchoconstriction, vasoconstriction, hypertension, nausea, and abdominal cramping. It is contraindicated in pregnancy because it induces uterine contraction. Site injection carries risks of local tissue reaction and accidental systemic absorption. This is not a compound with a benign research profile.
Protocol ranges
| Source tier | Amount | Frequency / duration | Notes |
|---|---|---|---|
| Label | Ophthalmic solution per label | Per prescribing information | Approved indication only |
| Label | Veterinary IM dosing per species | Per veterinary label | Livestock estrus synchronization |
| Cited range | Community figures circulating for site injection | — | No human evidence; high-risk claim |