Ingredient explainer

Methoxyestratetraenone (MEO-EST-ONE)

Evidence: Anecdotal

A disputed-identity "ketone" estratetraene that's reportedly just equilin — a horse estrogen. The running joke of the pheromone-molecule list, and one to skip.

Here's the punchline of the whole molecule list. Methoxyestratetraenone gets sold as an exotic "ketone" pheromone — but by the community's own accounting, what's actually in the bottle is reportedly equilin methyl ether. Equilin is a horse estrogen: the estrogen pulled from pregnant mares' urine, the same class of compound in Premarin (a name that is literally PREgnant MARes' urINe). So the "cutting-edge pheromone molecule" a vendor wants real money for is, allegedly, a horse hormone you'd be dabbing on your neck. We'll still cover it straight, but let's be honest up front: this is the one to laugh at and walk past.

What it is (and what's actually sold)

The name implies a 3-methoxy estratetraen-17-one — a ketone analogue of methoxyestratetraenol . But according to the community's own accounting, the material currently sold under this name is equilin methyl ether: the 3-methyl ether of equilin, a horse-derived estrogen (equilin is estra-1,3,5(10),7-tetraen-3-ol-17-one). Those are two different molecules wearing one marketing label, which is the core problem with buying it.

CAS number and chemistry

There is no single verifiable CAS that reliably corresponds to the intended “methoxyestratetraenone.” For reference, the horse estrogen equilin — the reported basis of what is actually sold — is CAS 474-86-2, and its methyl ether is the material in question. Presenting one tidy CAS for “methoxyestratetraenone” would paper over a real identity dispute, so we do not. This is a molecule to buy only from a vendor who will name, precisely, the compound in the bottle.

The estrogenic caution comes first here

Because the actual material is an equilin (horse-estrogen) derivative, its most concrete property is estrogenic activity. Community guidance is explicit: use it sparingly and apply it to clothing rather than skin, to limit absorption of an estrogen-active compound. On a page where the effect claims are murky, this safety point is the part to take seriously.

What wearers report

The community describes a modulatory, “MSG of pheromones” style effect — something that rounds out or amplifies a blend rather than carrying it. Those reports are hard to weigh given the identity confusion: if buyers are not all receiving the same molecule, the reports are not describing the same thing. Recorded, with that heavy caveat attached. The cleaner, better-identified sibling is methoxyestratetraenol .

Can a mechanism be offered?

Not honestly, while the identity is unsettled. If the material is equilin methyl ether, its defining action is estrogenic, not a demonstrated chemosignal effect — and estrogenicity is a reason for caution, not a selling point. A modulatory pheromone mechanism would require first knowing which molecule is actually present.

The honest read

The honest read: it's a joke, and not a clever one. A disputed-identity "pheromone" that's reportedly a horse estrogen, has no clean CAS you can verify, and carries a genuine estrogenic-exposure risk. There is no version of "rub mare-urine estrogen on yourself to get dates" that ends well. Skip it — and if a vendor is pushing this as their secret weapon, that tells you everything you need to know about the vendor.

How to buy it — if at all

If you are set on trying it, treat identity as the whole game. Ask the vendor exactly what the material is, whether it is equilin methyl ether, and for a CAS you can check — and expect that many sellers cannot answer cleanly, which is itself the answer. The far better-defined member of the pair is methoxyestratetraenol , which at least has a real CAS and a consistent identity.

Whatever you buy under this name, the estrogenic caution carries over and arguably intensifies: an equilin-derived compound is estrogen-active, so keep it off skin, apply any use to clothing, and use it sparingly. On a page where the effect claims are genuinely murky, that safety point is the one solid thing to hold onto.

FAQ

Does methoxyestratetraenone have a CAS number?

Not one that reliably matches the intended compound. What is actually sold is reportedly equilin methyl ether (equilin is CAS 474-86-2); the pheromone product's identity is disputed.

Is methoxyestratetraenone safe?

It is reportedly an estrogen-active (equilin-derived) compound, so community guidance is to apply it to clothing, not skin, and use it sparingly.

How is it different from methoxyestratetraenol?

Methoxyestratetraenol (MEO-EST) is a well-identified methyl ether with a real CAS; “methoxyestratetraenone” has a disputed identity and no clean CAS.

What is actually in a 'methoxyestratetraenone' product?

Reportedly equilin methyl ether, a horse-estrogen derivative — not necessarily the ketone the name implies. Because the identity is disputed, buyers may not all be getting the same molecule.

Is it worth using over methoxyestratetraenol?

Generally no. Methoxyestratetraenol is better-identified, has a real CAS, and carries the same social-buffer reputation without the identity dispute.

Is methoxyestratetraenone estrogenic?

The material actually sold is reportedly an equilin (horse-estrogen) derivative, so yes, it is best treated as estrogen-active. That is the practical reason for the community's clothing-not-skin guidance and for using it sparingly, if at all.

Why is the identity of methoxyestratetraenone disputed?

Because the name implies a ketone estratetraene, but the material commonly sold is reportedly equilin methyl ether, a horse-estrogen derivative — a different molecule. With no single verifiable CAS tying the name to one compound, buyers cannot be sure they are all getting the same thing, which is why the cleaner methoxyestratetraenol is the safer choice.