Short answer

We found no documented interaction between Biotin and NAC in the sources below. That isn't proof the combination is right for you: check each one's cautions, and ask your pharmacist if you take medication.

Biotin

What it is: A B vitamin that helps turn the food you eat into energy.

What the research says: It's widely sold for hair, skin and nails, but there's little evidence for that. A few small studies found harder nails in people with brittle nails.

Cautions

• High-dose biotin can make some lab tests wrong, including thyroid hormone tests. Tell your clinician before a blood test.

Medicines to check

• Long-term anti-seizure medicines can lower biotin levels

In Holitro: Biotin 5000mcg (5000 mcg per capsule)

Source: NIH Office of Dietary Supplements: Biotin: Fact Sheet for Consumers (updated January 2021)

NAC (N-acetylcysteine)

What it is: An antioxidant that's both a hospital medicine (for acetaminophen overdose) and a supplement.

What the research says: As a medicine it treats acetaminophen poisoning. As a supplement, results for lung conditions and as an add-on for depression are mixed.

Cautions

• It can cause stomach upset, nausea, diarrhea, tiredness or rash; less often low blood pressure or headache.

Medicines to check

• Nitroglycerin: don't combine (severe headaches, lower blood pressure)
• Antidepressants: animal studies suggest NAC may strengthen their effect
• Cancer treatment: check with your care team

In Holitro: NAC (600 mg per capsule)

Source: Memorial Sloan Kettering Cancer Center, About Herbs: N-Acetylcysteine (updated October 2022)

Check with your doctor or pharmacist, especially if you take medication.

Check your stack — free

Educational information only, not medical advice. This reflects general ingredient overlap, not a personalized safety review. Always check with your doctor or pharmacist before combining supplements, especially if you take medication, are pregnant or nursing, or manage a health condition. These statements have not been evaluated by the FDA.