Drug & supplement interaction

Nicotinamide Riboside + Promethazine

Promethazine brand name: Phenergan.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Nicotinamide Riboside and Promethazine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Nicotinamide Riboside and Promethazine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Promethazine and Nicotinamide Riboside in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Nicotinamide Riboside safety at a glance

Nicotinamide Ribos... overall Use caution Appears well tolerated in short-term studies, but long-term safety is not fully known.
Pregnancy Possibly Safe When nicotinamide riboside chloride is used orally and appropriately. The European Food Safety Authority has determined that taking nicotinamide riboside chlori... Read the full pregnancy detail
Breastfeeding Possibly Safe When nicotinamide riboside chloride is used orally and appropriately. The European Food Safety Authority has determined that taking nicotinamide riboside chlori... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Promethazine and Nicotinamide Riboside? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Promethazine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Promethazine is filed under 4 classifications — including phenothiazines, anticholinergic drugs, photosensitizing drugs. Nicotinamide Riboside has documented interactions with 1 drug class — the most serious being antihypertensive drugs (minor) — and none of Promethazine’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Nicotinamide Riboside Does Interact With Other Medications

Nicotinamide Riboside has 172 minor known drug interactions in our database — Promethazine isn’t one of them. If you take anything else, check it against the full list below.

Minor 172 No known interaction 2,658 (incl. Promethazine)
Taking anything else?

Check Another of Your Medications Against Nicotinamide Riboside

Covers the 2,830 medications we’ve checked against Nicotinamide Riboside. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Nicotinamide Riboside and Promethazine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Nausea reported in 11.7% of FDA reports for Promethazine Additional detail

    Nicotinamide Riboside

    “Orally, mild cases of nausea, bloating, and transient changes in stools have been reported in clinical trials for some patients taking nicotinamide riboside (Niagen, ChromaDex).

    Other gastrointestinal adverse effects such as abdominal discomfort, diarrhea, and dyspepsia have been reported with oral use of a combination product (Basis, Elysium Health) containing nicotinamide riboside and pterostilbene.”

    Nicotinamide Riboside · Natural Medicines adverse-effect record, reported in diarrhea.

    4 sources cited
    1. 94744. Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun 2018;9(1):1286. PubMed
    2. 94745. Dollerup OL, Christensen B, Svart M, et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. Am J Clin Nutr 2018;108(2):343-53. PubMed
    3. 102035. Conze D, Brenner C, Kruger CL. Safety and metabolism of long-term administration of NIAGEN (nicotinamide riboside chloride) in a randomized, double-blind, placebo-controlled clinical trial of healthy overweight adults. Sci Rep 2019;9(1):9772. PubMed
    4. 94747. Dellinger RW, Santos SR, Morris M, et al. Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safety and sustainably: a randomized, double-blind, placebo-controlled study. NPJ J Aging Mech Dis 2017;3:17.

    Promethazine

    Listed in the ADVERSE REACTIONS section of the FDA label for Promethazine, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • A skin rash Additional detail

    Nicotinamide Riboside

    “Orally, mild cases of flushing, skin rash, pruritus, and excessive sweating have been reported in clinical trials for some patients taking nicotinamide riboside (Niagen, ChromaDex). However, flushing and skin rash were reported at the same rate in patients receiving placebo.”

    Nicotinamide Riboside · Natural Medicines adverse-effect record, reported in pruritus.

    2 sources cited
    1. 94744. Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun 2018;9(1):1286. PubMed
    2. 94745. Dollerup OL, Christensen B, Svart M, et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. Am J Clin Nutr 2018;108(2):343-53. PubMed

    Promethazine

    Listed in the ADVERSE REACTIONS section of the FDA label for Promethazine. Read the label on DailyMed ›

Reported for Nicotinamide Riboside but not commonly for Promethazine: stomach upset, sweating, muscle pain and diarrhea.

Effects for Promethazine come from the ADVERSE REACTIONS section of its FDA label; effects for Nicotinamide Riboside come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 22,361 voluntary FDA FAERS reports for Promethazine that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Nicotinamide Riboside in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Safe

When nicotinamide riboside chloride is used orally and appropriately. The European Food Safety Authority has determined that taking nicotinamide riboside chloride in doses of up to 230 mg daily is safe when pregnant or breastfeeding.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Nicotinamide Riboside or Promethazine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Nicotinamide Riboside or Promethazine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Promethazine

This page covers Nicotinamide Riboside only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Promethazine page lists 83 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 23 minor.

From our pharmacist’s overview on the Promethazine page

“Promethazine (Phenergan) is a phenothiazine antihistamine used for allergies, nausea, and motion sickness, and it is strongly anticholinergic on its own, causing dry mouth, blurred vision, drowsiness, and constipation. That is why the 83 supplements and herbs on this list deserve real attention, starting with the three rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Promethazine interaction page

One more smart check

Taking Nicotinamide Riboside as Part of a Dietary Supplement Product? Check It for Interactions

We hold 162 real supplement products containing Nicotinamide Riboside, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Nicotinamide Riboside. Even though Nicotinamide Riboside itself has no known interaction with Promethazine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Nicotinamide Riboside and Promethazine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Nicotinamide Riboside
Top half

#526 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Promethazine
Top half

#1,204 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Nicotinamide Riboside reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Nicotinamide Riboside and Promethazine records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Nicotinamide Riboside

What is Nicotinamide Riboside?

  • Healthy aging
  • Boosting cellular energy
  • Supporting metabolism
  • General wellness
  • Athletic recovery

Nicotinamide riboside (NR) is a form of vitamin B3 that the body converts into NAD+, a molecule involved in cellular energy and repair. Early human studies show it can reliably raise NAD+ levels and appears generally well tolerated, but solid evidence that it improves aging, energy, or specific health conditions is still limited. Talk with your pharmacist or doctor before starting it.

Not applicable (a form of vitamin B3) · Capsules, tablets, powders

An interaction check asks whether these two react with each other — it does not ask whether Nicotinamide Riboside is a good idea for someone in your situation. Here is what our Nicotinamide Riboside record says about it on its own.

Nicotinamide Riboside: dosing

There is no official, standardized dose of nicotinamide riboside for any health condition. Research studies have used a range of amounts, but these are not formal recommendations.The safest approach is to follow the dose printed on the product label and not exceed it without professional guidance. They can help you decide whether NR is appropriate for you and what amount makes sense.

From our Nicotinamide Riboside monograph — the full record covers uses, side effects and every documented interaction.

Read the full Nicotinamide Riboside monograph & all interactions
Medication

About Promethazine

What Is Promethazine Used For?

Brand name: Phenergan

Promethazine is used for a wide range of conditions. Tablets, oral solution, and rectal suppositories (brands including Phenergan, Promethegan, and Phenadoz) are approved for seasonal and perennial allergic rhinitis, vasomotor rhinitis, allergic conjunctivitis, hives (urticaria), angioedema, dermographism, and allergic reactions to blood or plasma. They are also used for motion sickness (both prevention and active treatment), nausea and vomiting related to anesthesia and surgery, sedation, and as a helper medication alongside pain relievers after surgery.

Promethazine hydrochloride injection (brands including Phenergan and Promethazine HCl injection) is used for many of the same purposes but is reserved for situations where oral treatment is not possible — including allergic emergencies as an adjunct to epinephrine, sedation during labor, and as an aid during certain surgical procedures such as bronchoscopy and eye surgery.

Most-Reported Side Effects for Promethazine

From FAERS, the FDA’s public side-effect reporting system (22,614 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dependence 3,586 reports
Nausea 2,646 reports
Vomiting 1,802 reports
Fatigue 1,496 reports
Diarrhea 1,341 reports
See full Promethazine drug information
Keep checking

Other Drugs & Nicotinamide Riboside

Browse every other medication we’ve checked against Nicotinamide Riboside — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
172Minor
2,657No known interaction
172 Minor 2,657 No interaction
Minor

172 interactions

Showing 60 of 172 minor interactions — see all 172 on the Nicotinamide Riboside page.

No interaction 2,657 drugs checked — show the list

We also checked Nicotinamide Riboside against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,657 medications checked with no known interaction — see the full Nicotinamide Riboside list.

See the full Nicotinamide Riboside interactions page
See every supplement checked against Promethazine, ranked by severity
Evidence & sources

Nicotinamide Riboside References

The 7 references that drive our Nicotinamide Riboside monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Martens CR, Denman BA, Mazzo MR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun 2018;9(1):1286. PubMed
  2. Dollerup OL, Christensen B, Svart M, et al. A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects. Am J Clin Nutr 2018;108(2):343-53. PubMed
  3. Dellinger RW, Santos SR, Morris M, et al. Repeat dose NRPT (nicotinamide riboside and pterostilbene) increases NAD+ levels in humans safety and sustainably: a randomized, double-blind, placebo-controlled study. NPJ J Aging Mech Dis 2017;3:17.
  4. Conze D, Brenner C, Kruger CL. Safety and metabolism of long-term administration of NIAGEN (nicotinamide riboside chloride) in a randomized, double-blind, placebo-controlled clinical trial of healthy overweight adults. Sci Rep 2019;9(1):9772. PubMed
  5. Remie CME, Roumans KHM, Moonen MPB, et al. Nicotinamide riboside supplementation alters body composition and skeletal muscle acetylcarnitine concentrations in healthy obese humans. Am J Clin Nutr. 2020;112(2):413-426. PubMed
  6. Turck D, Castenmiller J, de Henauw S, et al. Safety of nicotinamide riboside chloride as a novel food pursuant to Regulation (EU) 2015/2283 and bioavailability of nicotinamide from this source, in the context of Directive 2002/46/EC. EFSA J. 2019;17(8):e0
  7. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, et al. Extension of use of nicotinamide riboside chloride as a novel food pursuant to Regulation (EU) 2015/2283. EFSA J 2021;19(11):e06843.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Nicotinamide Riboside and Promethazine Together: Common Questions

Is it safe to take Nicotinamide Riboside with Promethazine?
We do not list a known interaction between Nicotinamide Riboside and Promethazine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Nicotinamide Riboside and Promethazine have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Nicotinamide Riboside and Promethazine combination checked?
Interactions in our licensed database are recorded against drug classes. Promethazine is filed under 4 classifications, and Nicotinamide Riboside has documented interactions with 1 drug class — none of Promethazine's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Nicotinamide Riboside interact with any other medications?
Yes. Nicotinamide Riboside has 172 documented drug interactions in our database — Promethazine is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Promethazine interact with any supplements?
Yes. Promethazine has documented interactions with 83 supplements in our database — Nicotinamide Riboside is not one of them. The Promethazine interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Nicotinamide Riboside monograph Uses, safety profile, and every drug interaction in one place Promethazine drug information The full plain-English guide to this medication Promethazine supplement interactions Every supplement checked against Promethazine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Promethazine and Nicotinamide Riboside?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.