Longevity15 by Pet's Best Life is a canine supplement containing C15:0 (pentadecanoic acid), an odd-chain saturated fatty acid. The product delivers this fatty acid component in a concentrated form at greater than 99.5% purity. C15:0 is naturally found in certain dairy fats but occurs in limited quantities in typical canine diets.

This supplement is formulated as a daily addition to dogs' feeding routines. The product comes in size-specific variants to accommodate different dog weights: Extra Small for dogs under 13 pounds, Small for dogs 13-25 pounds, Medium for dogs 26-50 pounds, and Large for dogs over 51 pounds.

The supplement was developed by veterinarians and contains the isolated fatty acid in a shelf-stable format. Pet's Best Life designed this product as a source of C15:0 for dogs whose bodies do not naturally produce this particular fatty acid compound.