No. It was proposed as a possible new vitamin in the early 2000s, but the claim did not hold up, and it has never been classified as one. No human deficiency state has been identified, which is part of why the vitamin case failed.

Is 10 mg of PQQ as good as 20 mg?

There is no trial evidence for 10 mg. Every study that found anything used 20 mg, so a 10 mg product is untested rather than a gentler version of a known dose. 20 is also the assessed safe maximum, so there is no case for going higher.

Does PQQ keep you awake?

Some people report feeling stimulated and take it earlier in the day. One uncontrolled study reported improved sleep quality, so the picture is mixed. But both sides are anecdote or weak evidence rather than anything a controlled trial has established.

PQQ or NMN and nicotinamide riboside?

These supplements get grouped together by many manufacturers, but there is no good reason why. PQQ is not an NAD precursor and works by a different mechanism from either. All three have thinner human evidence than their marketing implies, so this is not a question with a winner so much as three open questions.

Can you take PQQ with astaxanthin or alpha-lipoic acid?

No known problem with either. Both astaxanthin and alpha-lipoic acid turn up in the same sort of formulas, and nothing suggests they interfere with each other. But stacking antioxidants has considerably less evidence behind it than many products imply.

How long before you would notice anything?

The best PQQ trials ran from 8 to 12 weeks, so give it that long at minimum. Be prepared for the honest answer: those studies measured changes on cognitive tests rather than anything participants reported feeling. You may not notice a subjective difference.

PQQ Review: Benefits, Dosage & Evidence