This awfully long named ingredient is, in fact, a pretty small molecule. It's a tripeptide (a three amino acid peptide) with molecular weight less than 500 Da, meaning that it's small enough to penetrate nicely and easily into the skin.
It belongs to the "Botox in a jar" type of peptides (similar to Argireline or Leuphasyl) targeting wrinkles caused by facial movements, like laughter lines or crow’s feet. According to the manufacturer's in-vivo (made on real people) studies, 4% Syn-Ake used for 28 days resulted in 21% smoother and 15-20% less wrinkled skin with max values up to 52%. The smoothing effect was measurable on 80% of the volunteers, while the wrinkle reduction effect was evident on 73%.