A four amino acid peptide that is claimed to improve puffy eye bags via its anti-oedema and anti-glycation effects.
To back this claim up, the manufacturer created an in-vivo study with 20 volunteers using 10% of EYESERYL (that comes down to 0.01% (!) of the pure peptide) and found that by day 15, 70% of the volunteers improved, while 95% of the volunteers improved by the end of the study (60 days). About third of them improved only slightly, third of them showed an ok improvement and third showed a good improvement. They also have pretty convincing before and after photos, so we can tell you that for the lucky ones, the improvement can be real and visible.
But, the thing is that puffiness around the eyes can have multiple reasons and one of the major ones is fat accumulation that might happen as we age. No miracle cream or ingredient can do much about that, however, another common reason is water accumulation. If the reason behind your eye bags is this latter one, trying an eye cream with Acetyl Tetrapeptide-5 can be a good idea and might bring nice improvements.