Why is my BPC vial yellow? I thought it was supposed to be clear

@hexaclinic the powder itself. pre-reconstitution. Other vials same supplier are pure white.

Yellow dry powder = could be many things, most benign (excipient differences, minor oxidation that doesn't affect potency). Yellow or cloudy solution after bac water = I'd toss.

Is it reconstituted yet? Dry powder BPC is white/off-white. Clear when reconstituted. A faintly yellow tint in lyophilized powder CAN be normal (mannitol or other excipients) but a yellow SOLUTION post-reconstitution is iffy.

Could be a stability issue, could be a different batch. If I had it I'd reconstitute it, see if the solution is clear. If clear, it's probably fine. If yellow post-reconstitution, don't use it.

Ask the supplier for a COA for that batch. Good suppliers will send it. Also, take a photo of both vials side by side and email it to them. Most will replace if legit concern.

@protocolpilot emailed them. will report back.

I had the exact same thing 2 months ago. Supplier sent a COA, the tinted vial was from a different lot. Tested fine. I used it with no issues.

@showmethestudy the supplier's COA showed 98% purity for both lots. sorry should have been clearer.

"Tested fine" according to what? Eyeballing the solution and not feeling sick isn't a potency test.

UPDATE: supplier responded, sent COA, different lot, tested 97.8%. Clear solution when reconstituted. Using it.

thank god I found this thread. mine is also kind of off-white and I've been stressing. will email the supplier.

Flagging for anyone reading later: supplier-provided COAs have obvious conflict of interest problems. They're better than nothing but not a substitute for independent testing.

@nullhypothesis agreed, though independent HPLC testing is cost-prohibitive for most hobbyists. Best practical bet is: reputable supplier + their COAs + community reputation + eyeballs on the product.

2 weeks in, vial behaving normally, healing as expected. closing the loop for anyone who finds this thread via search.

This is the type of thread I search this forum for. clear problem, actual troubleshooting, closure. thanks.