Drug & supplement interaction

Nicotinamide Riboside + Cephalexin

Cephalexin brand names: Keflex, Keftab, Cephalex, Lexin.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Nicotinamide Riboside and Cephalexin 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 Cephalexin

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 Cephalexin 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 Cephalexin and Nicotinamide Riboside? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cephalexin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cephalexin is filed under 7 classifications — including organic anion transporter 3 (oat3) substrates, organic anion transporter 1 (oat1) substrates, antibiotic drugs. Nicotinamide Riboside has documented interactions with 1 drug class — the most serious being antihypertensive drugs (minor) — and none of Cephalexin’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 — Cephalexin 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. Cephalexin)
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 Cephalexin 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.

  • Stomach upset / Diarrhea 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.

    Cephalexin

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

  • Itching 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

    Cephalexin

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

  • Nausea Additional detail

    Nicotinamide Riboside

    Recorded for Nicotinamide Riboside in the same Natural Medicines adverse-effect record shown under Itching above.

    Cephalexin

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

Reported for Nicotinamide Riboside but not commonly for Cephalexin: sweating, muscle pain, a skin rash and bloating or gas.

Effects for Cephalexin come from the ADVERSE REACTIONS section of its FDA label; effects for Nicotinamide Riboside come from the Natural Medicines adverse-effect record, quoted above. 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 Cephalexin

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 Cephalexin, 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 Cephalexin

This page covers Nicotinamide Riboside only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cephalexin page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate) and Aristolochia (moderate).

By severity: 3 major · 47 moderate · 11 minor.

From our pharmacist’s overview on the Cephalexin page

“Cephalexin (Keflex) is one of the most commonly prescribed oral antibiotics, usually for skin and urinary infections, and its supplement list warrants genuine care rather than a quick skim. Three of the 61 ingredients on file rate major.”

Reviewed by 2 · Jul 18, 2026

Open the Cephalexin 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 Cephalexin, 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 Cephalexin 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

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

29 days ago today
Medication Cephalexin
Top 5%

#67 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 13, 2026. The Nicotinamide Riboside and Cephalexin 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 Cephalexin

What Is Cephalexin Used For?

Brand names: Keflex, Keftab, Cephalex, Lexin

Cephalexin treats bacterial infections caused by susceptible strains of bacteria. It is used for respiratory tract infections, ear infections (otitis media), skin and skin structure infections, bone infections, and genitourinary tract infections — including acute prostatitis.

It works only against bacterial infections — not viruses like colds or flu. Your prescriber should use it only when a bacterial infection is confirmed or strongly suspected, to help prevent antibiotic resistance.

Most-Reported Side Effects for Cephalexin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Chronic kidney disease 2,157 reports
Renal failure 1,558 reports
Acute kidney injury 1,550 reports
Diarrhea 1,405 reports
Fatigue 1,303 reports
See full Cephalexin 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 Cephalexin, 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 Cephalexin Together: Common Questions

Is it safe to take Nicotinamide Riboside with Cephalexin?
We do not list a known interaction between Nicotinamide Riboside and Cephalexin. 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 Cephalexin have any of the same side effects?
Yes — our sources link each of them separately to 4 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 Cephalexin combination checked?
Interactions in our licensed database are recorded against drug classes. Cephalexin is filed under 7 classifications, and Nicotinamide Riboside has documented interactions with 1 drug class — none of Cephalexin'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 — Cephalexin 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 Cephalexin interact with any supplements?
Yes. Cephalexin has documented interactions with 61 supplements in our database — Nicotinamide Riboside is not one of them. The Cephalexin 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 Cephalexin drug information The full plain-English guide to this medication Cephalexin supplement interactions Every supplement checked against Cephalexin, 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 Cephalexin 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.