What is pentadecanoic acid?

Pentadecanoic acid, or C15:0, is a saturated fatty acid found mostly in dairy fat. Fatty15 supplies it in capsule form for people who want it without dairy.

How do I take Fatty15?

The label dosage is one capsule daily. Take it with a meal and follow the bottle directions.

Yes. The capsule is vegetable cellulose and the product is listed as vegan, with no dairy ingredients.

Is $92.99 a good price for Fatty15?

It is the only new price listed, $92.99 at eBay as of November 8, 2026, so there is no lower store price to compare against. Check the bottle size before judging the per-capsule cost.

Will Fatty15 help me sleep or give me energy?

The brand markets it for energy, mental clarity and sleep support, but these are claims, not established effects. Treat it as a supplement, not a treatment for sleep problems.

Where is the Fatty15 cheapest?

At eBay, for $92.99, as of our latest check.

Where can I buy the Fatty15?

3 stores we checked sell it, including eBay, austin-skin-wellness.myshopify.com, fatty15.

Seraphina Therapeutics

Fatty15

Best price now

$92.99at eBayObserved at 3:13 PM

Prices are checked against each store and labelled with when. Store links may earn us a commission.

Visit eBay

Ask our agent about this product

It checks today's price at every store, compares the alternatives and answers in about a minute.

Our take on the Fatty15

Fatty15 is a once-daily capsule supplement from Seraphina Therapeutics built around pentadecanoic acid (C15:0), a saturated fatty acid found in dairy fat. It is marketed for energy, mental clarity and sleep support, and the only other ingredient is a vegetable cellulose capsule, so it is vegan. The best new price is $92.99 at eBay as of November 8, 2026, and only one store lists it new, so there is little price competition to shop around.