Niacinamide
Also known as: Nicotinamide, Vitamin B3 amide
Niacinamide is a form of vitamin B3 that, unlike the flushing form of niacin, does not typically cause the skin-flushing reaction. It appears in skin-wellness and general-nutrition discussions. Evidence for supplementation beyond correcting a deficiency is limited. Importantly, high doses have their own liver-related discussions in the literature that are distinct from the separate concerns around flushing niacin, so staying within commonly cited limits matters.
Snapshot
What this page can tell you: NIH ODS figures for niacin's upper limit, how niacinamide differs from flushing niacin, and its high-dose liver/GI effects.
What it cannot: That niacinamide improves skin or any condition as a personal recommendation — evidence beyond correcting deficiency is limited. Informational only.
🧩 Stack insights — how this fits into a schedule
High-dose niacinamide (liver) — NIH ODS: niacinamide has fewer side effects than flushing niacin, but ≥500 mg/day can cause diarrhea and easy bruising, and ≥3,000 mg/day can cause nausea, vomiting, and liver damage. The niacin upper limit (nicotinic acid) is 35 mg/day. Keep amounts modest and review with a clinician.
Niacinamide vs flushing niacin — NIH ODS: nicotinamide (niacinamide) does not cause the flushing that nicotinic acid does (flushing appears at ≥30 mg nicotinic acid). They are different forms with different profiles — don't apply information about one to the other.
Relationship insights are informational only — they describe what is commonly discussed or studied, not what you should take. Not medical advice; review your routine with a clinician or pharmacist.
🧭 How niacinamide caution scales with the amount
| Amount | Caution level | Note |
|---|---|---|
| Modest amounts | Low–Moderate | Niacinamide does not cause the flushing that nicotinic acid does. |
| ≥500 mg/day | Moderate | NIH ODS: can cause diarrhea and easy bruising. |
| ≥3,000 mg/day | High | NIH ODS: can cause nausea, vomiting, and liver damage. |
The niacin (nicotinic acid) upper limit is 35 mg/day. Official figures, not a personal recommendation.
🕒 Timing
When: With a meal
Food: With food
Commonly taken with food; timing is otherwise flexible.
💊 Common use range
Varies widely by use mg
High doses are associated with liver-related discussions; a commonly cited adult upper limit for niacin forms is around 35 mg/day for the effects used to set it — verify this figure and avoid high doses without professional guidance.
Ranges are informational, not a recommended dose. Talk to a professional about what is right for you.
⚠️ Commonly noted interactions (supplements)
None listed.
Often about absorption or timing rather than danger — separating doses is common. This list is not exhaustive.
🧭 Caution level
Ask a clinician or pharmacist before use.
- Liver caution category
- Commonly discussed upper limit
- Higher caution if you have a liver condition
Caution level is an informational summary of commonly discussed caution categories and doses — not a safety rating, approval, or medical advice. Low caution does not mean safe for you.
🩺 Medication caution categories
- Liver conditions (health condition)
🏥 Surgery & procedure caution
Not a well-established surgical concern; share your full supplement list with your care team.
If you have a procedure scheduled, bring your full supplement list to your surgical and anesthesia team. Do not stop prescribed medication unless your clinician tells you to. Do not start or stop supplements based only on this app.
✅ Quality checklist
- Prefer products with third-party testing or a certificate of analysis (COA).
- Check the label for the exact form and the elemental or active amount per serving.
🧩 Commonly paired with
🔁 Alternatives
🗣️ Questions for a professional
- Given my liver health, is any dose of niacinamide appropriate for me?
🛡️ Safety notes (source-reviewed)
- NIH ODS: niacin upper limit is 35 mg/day (set on nicotinic-acid flushing, seen at ≥30 mg).
- Niacinamide has fewer side effects but ≥500 mg/day can cause diarrhea and easy bruising; ≥3,000 mg/day can cause liver damage.
- Long-term extended-release nicotinic acid can cause liver problems; high-dose nicotinic acid can raise blood sugar.
⚖️ Evidence limitations
- Niacinamide and flushing niacin are different forms — don't apply information about one to the other.
❓ Frequently asked
Is niacinamide the same as niacin?
They are both vitamin B3 but different forms. NIH ODS notes niacinamide (nicotinamide) doesn't cause the flushing that nicotinic acid does. Their side-effect profiles differ, so don't apply information about one to the other.
How much niacinamide is too much?
NIH ODS notes ≥500 mg/day can cause diarrhea and easy bruising, and ≥3,000 mg/day can cause nausea, vomiting, and liver damage. The niacin upper limit is 35 mg/day.
🔬 Evidence snapshot
Overall evidence level here is listed as "Limited evidence". A detailed, source-reviewed evidence summary has not been completed yet.
🚦 Commonly noted cautions (auto)
Liver caution category. This item carries a liver caution category (commonly discussed for concentrated extracts). If you have a liver condition or notice unusual symptoms, consider discussing it with a healthcare professional. This is a general caution, not a diagnosis or medical instruction.
🧪 Forms & quality
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
See the supplement glossary for what form names like "L-", chelated, or standardized extract mean.
📏 Dose & monitoring
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
Evidence vs. burden: Not yet reviewed
Labs that may be worth discussing: Liver enzymes
These are discussion prompts, not required tests. A healthcare professional can advise what makes sense for you.
😐 Commonly reported side effects
- Digestive upset
- At high doses, liver-related effects are discussed
Non-exhaustive and individual.
🔄 Cycling & breaks
No established cycling pattern.
📅 Daily use notes
Niacinamide and flushing niacin are different forms with different profiles; do not treat information about one as applying to the other.
📋 Source review status
Source-reviewed — last reviewed 2026-07-03
Reviewed against the NIH ODS niacin consumer fact sheet; editorial pass still pending.
Research backlog (queries to verify):
- niacinamide skin health human evidence
- niacinamide high dose liver safety
- niacinamide versus niacin flushing difference
📚 References
- NIH ODS — Niacin (Consumer Fact Sheet)NIH ODS — Full text reviewed 2026-07-03. Verified: adult UL 35 mg/day from supplements (set on nicotinic-acid flushing; ≥30 mg nicotinic acid causes flushing); nicotinamide/niacinamide has fewer side effects but ≥500 mg/day can cause diarrhea and easy bruising and ≥3,000 mg/day nausea/vomiting/liver damage; long-term extended-release nicotinic acid can cause hepatitis/liver failure; isoniazid/pyrazinamide interfere with niacin; high-dose nicotinic acid (≥1,500 mg) can raise blood sugar and interfere with diabetes medicines.
Verified against the source shown. See the research-status page for how review works.
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