They have Great deals on everything. Though I haven't researched on the GHK-CU or GLP-3 yet their COA's looked good. I took off a star because they took 3 days to actually drop it off at USPS. But I received it in the mail in 3 days after that. The packaging is pretty basic, like a fledgling company on a shoestring budget. But opening the package was like messing with one of those Russian nesting dolls, went through 4 layers of packaging to get to my little baby vials. Would probably buy again from them tho.