Yarai › Conflict library › Niacinamide and exfoliating acids
Yes. This pair is fine together, and Yarai deliberately does not flag it.
Not a conflict. Fine together. There are no niacinamide pairwise rules in the engine at all.
Another pairing that gets separated for no good reason, usually on the strength of an argument about pH. Niacinamide is well tolerated alongside exfoliating acids, and the two show up together in plenty of finished formulas. Yarai carries no niacinamide rules whatsoever.
| Status | Not a conflict. No rule exists in the engine for this pair. |
| Basis | Internal evidence review |
We went looking for evidence that this pairing causes a problem and did not find any worth acting on, so there is no rule for it. That absence is recorded deliberately, in the same file as the rules we do carry, so it cannot drift back in as folklore.
Most ingredient apps grow their conflict list forever, because adding a warning feels responsible and removing one feels risky. A rule that turns out to be wrong is worse than no rule: it sends you rearranging a routine that was already fine. Yarai's list is shorter on purpose, and what we removed is written down in the same file as what we kept.
The concern is theoretical and does not hold up in the way it gets repeated. Formulators combine them routinely. If it were the problem it is described as, those products would not exist.
Answering a single question like this one is straightforward. The harder question is the one you actually have: not whether these two work together, but whether the seven things on your shelf work together. Conflicts compound. Two moderate ones in the same evening are not two separate problems, they're one irritated face, and no single-pair answer anywhere on the internet can tell you that.
Yarai scans your products, builds them into an AM and PM routine, and checks every product against every other one, using these same graded rules with the same sources attached. You get the whole picture rather than one pair at a time.
More pairs: Retinol and glycolic acid, Retinol and salicylic acid, Retinol and lactic acid. Or see the full conflict library.