Dr.PulmRoch said:

Vendor quality matters when discussing certificates of analysis.

I tested my certificates of analysis batch through Janoshik — 99.2% purity. That's within acceptable range for compounded peptides. Turnaround was 14 business days.

The test costs ~$122 but gives you actual HPLC chromatography data plus mass spec confirmation. For the peace of mind alone, it's worth every penny. I test every new batch from a new vendor.

Adding the numbers, since they settle part of this. Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a trend.

Following on from Dr.PulmRoch — and this may be the naive question:

What did you change at the same time, and can you separate the two now?

bri_stats said:

Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a…

Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. Pushing back on the consensus forming here. Consistency is not the same as correctness, and a board that agrees with itself quickly is usually agreeing with the first person who sounded certain.

bri_stats said:

Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a…

Agreed on the substance. I would put less weight on the timescale, because two months of anything is not enough to distinguish a trend from a wobble.