I've tried MK-677, CJC-1295/dac, and BPC 157, each one more than once each, and bought from multiple vendors. Here's my take on these products:
MK-677 - I've bought this from 2 different vendors, product was identical in both cases. But I don't believe what's being sold as MK-677 is the same molecule described in the published studies. MK-677 is a "ghrelin like mimetic" and what people are getting likely *is* the much cheaper to manufacture ghrelin itself. What's being sold as MK-677 is probably all coming from the same lab in China, and then passed off as MK-677. The biggest clue: Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man. I have yet to read a report by anyone that MK-677, when taken just before bed. improved their sleep quality. In my case it made it much worse and this seems to be a consistent finding for most people reporting their results. Conclusion: Most stuff being sold as MK-677 is fake.
CJC-1295/with dac : I've purchased this 4 times iirc. Twice it was the real deal, and twice it was completely fake, bunk. When it worked the effects were noticeable, but effective dosing for any length of time will be expensive. Have no intention of buying this again.
BPC-157: I've bought this twice and noticed nothing. I believe it was completely fake. If this product was really available at reasonable prices we'd be hearing a lot more about it since the research has been incredibly promising. But I've never come across any positive reports by actual users that couldn't be written off as placebo effect.
Remember, this entire "Research Chemicals" business runs on the "honor" system. They all state very plainly that their products are not for human consumption. They can sell you anything they want and call it anything they want.
I've never tried exogenous HGH and don't think it is necessary. For most people the pituitary gland does not lose its ability to produce GH, it's just that the signal to do so fades as we age. But fasting has proven to be a great booster of this GH production signal. A 24 hour fast will boost GH production by 1000% in men and 500% in women. These studies have been replicated. Why not go with what works?