Answering this needs to know what is already in place, because the marginal value of each step depends on which are missing.
Material risk is reduced by independent testing: identity, purity and quantified content on your own lot, before committing to a larger order. That is the only step that addresses what is actually in the vial.
Know the symptoms that end the discussion: severe epigastric pain radiating to the back, persistent vomiting with reduced urine output, spreading redness with fever, jaundice, chest pain or breathlessness.
Nothing here is medical advice, and research-use compounds are not approved for human use in any jurisdiction.
Start lower and go slower than the label. Time costs nothing here.
5Worth flagging that comparing across laboratories is comparing laboratories, not suppliers. – tri_gly_ala 7 months ago add a comment