Drug & supplement interaction

Inositol Nicotinate + Valacyclovir

Valacyclovir brand name: Valtrex.

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 Inositol Nicotinate and Valacyclovir 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

Inositol Nicotinate and Valacyclovir

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 Valacyclovir and Inositol Nicotinate 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.

Inositol Nicotinate safety at a glance

Inositol Nicotinat... overall Use caution Generally tolerated short-term but evidence is limited and high-dose niacin compounds can affect the liver.
Pregnancy Avoid Not enough safety data; avoid unless directed by your doctor.
Breastfeeding Avoid Safety has not been established; best to avoid.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Valacyclovir and Inositol Nicotinate? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Valacyclovir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Valacyclovir is filed under 3 classifications — organic anion transporter 1 (oat1) substrates, seizure threshold lowering drugs, oral drugs. Inositol Nicotinate has documented interactions with 4 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and hmg-coa reductase inhibitors ("statins") (moderate) — and none of Valacyclovir’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

Inositol Nicotinate Does Interact With Other Medications

Inositol Nicotinate has 223 moderate known drug interactions in our database — Valacyclovir isn’t one of them. If you take anything else, check it against the full list below.

Moderate 223 No known interaction 2,607 (incl. Valacyclovir)
Taking anything else?

Check Another of Your Medications Against Inositol Nicotinate

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

What to actually watch for

No Interaction Found — But Data Suggests Inositol Nicotinate and Valacyclovir 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. One of them is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    Inositol Nicotinate

    “Orally, inositol nicotinate is converted to niacin and is therefore likely to cause similar side effects as niacin. Niacin is associated with elevated liver function tests and jaundice, especially with doses of 3 grams daily or more, and when doses are rapidly increased. Because inositol nicotinate is converted to niacin, it may also cause hepatotoxicity”

    Inositol Nicotinate · Natural Medicines adverse-effect record, reported in neonatal jaundice.

    5 sources cited
    1. 496. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
    2. 4458. Knodel LC, Talbert RL. Adverse effects of hypolipidaemic drugs. Med Toxicol 1987;2:10-32. PubMed
    3. 4863. American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
    4. 6243. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
    5. 11690. Figge HL, Figge J, Souney PF, et al. Nicotinic acid: a review of its clinical use in the treatment of lipid disorders. Pharmacotherapy 1988;8:287-94. PubMed

    Valacyclovir

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

  • Itching Additional detail

    Inositol Nicotinate

    “Orally, inositol nicotinate is converted to niacin and is therefore likely to cause similar side effects as niacin, including pruritus.”

    Inositol Nicotinate · Natural Medicines adverse-effect record, reported in pruritus.

    1 source cited
    1. 496. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.

    Valacyclovir

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

  • Stomach pain Additional detail

    Inositol Nicotinate

    “Orally, inositol nicotinate is generally well tolerated.

    Most Common Adverse Effects:

    Orally: Abdominal pain, constipation, diarrhea, flushing, heartburn, liver enzyme elevation, nausea, vomiting.”

    Inositol Nicotinate · Natural Medicines adverse-effect record, reported in constipation.

    Valacyclovir

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

  • Diarrhea / Vomiting / Nausea Additional detail

    Inositol Nicotinate

    “Orally, inositol nicotinate is converted to niacin and is therefore likely to cause similar side effects as niacin, including gastrointestinal complaints such as nausea, vomiting, bloating, heartburn, diarrhea, and constipation. These adverse effects from niacin may be reduced by taking it with meals or antacids, and usually disappear within two weeks of continued therapy.”

    Inositol Nicotinate · Natural Medicines adverse-effect record, reported in constipation.

    4 sources cited
    1. 496. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
    2. 4851. Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
    3. 11690. Figge HL, Figge J, Souney PF, et al. Nicotinic acid: a review of its clinical use in the treatment of lipid disorders. Pharmacotherapy 1988;8:287-94. PubMed
    4. 26094. Brown WV. Niacin for lipid disorders. Indications, effectiveness, and safety. Postgrad Med. 1995 Aug;98(2):185-9, 192-3. PubMed

    Valacyclovir

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

Reported for Inositol Nicotinate but not commonly for Valacyclovir: constipation, heartburn, bloating or gas and flushing.

Effects for Valacyclovir come from the ADVERSE REACTIONS section of its FDA label; effects for Inositol Nicotinate 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.

From our Q&A

Questions About Inositol Nicotinate or Valacyclovir

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Inositol Nicotinate or Valacyclovir, 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 Valacyclovir

This page covers Inositol Nicotinate only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valacyclovir page lists 27 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), African Wild Potato (moderate), Banderol (moderate), Biofeedback (moderate) and Caffeic Acid (moderate).

By severity: 1 major · 17 moderate · 9 minor.

From our pharmacist’s overview on the Valacyclovir page

“Valacyclovir (Valtrex) works against herpes outbreaks only if enough of it gets absorbed into your blood, and most of this list threatens exactly that. Of the 27 supplements on file, 17 can change how well oral medicines like this one are absorbed, and the single major-rated entry, activated charcoal, binds drugs in the gut outright.”

Reviewed by 2 · Jul 18, 2026

Open the Valacyclovir interaction page

One more smart check

Taking Inositol Nicotinate as Part of a Dietary Supplement Product? Check It for Interactions

We hold 202 real supplement products containing Inositol Nicotinate, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Inositol Nicotinate. Even though Inositol Nicotinate itself has no known interaction with Valacyclovir, 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 Inositol Nicotinate and Valacyclovir 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 Inositol Nicotinate
Top 25%

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

29 days ago today
Medication Valacyclovir
Top 5%

#31 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 Inositol Nicotinate reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Inositol Nicotinate and Valacyclovir 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 Inositol Nicotinate

What is Inositol Nicotinate?

Inositol Nicotinate
  • Cholesterol support
  • Improving circulation
  • Raynaud's phenomenon
  • Intermittent claudication (leg pain with walking)
  • A 'no-flush' niacin alternative

Inositol nicotinate is a 'no-flush' form of niacin marketed for cholesterol and circulation. Evidence that it works as well as regular niacin is weak and inconsistent, and it is not a proven replacement for prescription cholesterol treatment. Talk to your pharmacist or doctor before using it, especially if you have liver problems or take other medicines.

Synthetic compound (inositol bound to niacin/nicotinic acid) · Tablets, capsules

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

Inositol Nicotinate: dosing

There is no well-established standard dose for inositol nicotinate, and products vary widely. Do not assume a higher dose is safer or more effective.

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

Read the full Inositol Nicotinate monograph & all interactions
Medication

About Valacyclovir

What Is Valacyclovir Used For?

Brand name: Valtrex

Valacyclovir tablets are used in adults to treat cold sores (herpes labialis), genital herpes (initial and recurrent episodes), and shingles (herpes zoster). They can also be taken daily as suppressive therapy to reduce how often genital herpes outbreaks occur, and to lower the risk of passing genital herpes to a partner.

In children and adolescents, valacyclovir tablets are used to treat cold sores in those aged 12 and older, and chickenpox in those aged 2 to under 18. Valacyclovir has not been established as safe and effective for most uses in immunocompromised patients, with the exception of suppressive therapy for genital herpes in HIV-infected adults.

Most-Reported Side Effects for Valacyclovir

From FAERS, the FDA’s public side-effect reporting system (70,056 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 4,317 reports
Nausea 3,985 reports
Diarrhea 3,648 reports
Headache 2,964 reports
Fever 2,753 reports
See full Valacyclovir drug information
Keep checking

Other Drugs & Inositol Nicotinate

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

0Major
223Moderate
0Minor
2,606No known interaction
223 Moderate 2,606 No interaction
Moderate

223 interactions

Showing 60 of 223 moderate interactions — see all 223 on the Inositol Nicotinate page.

No interaction 2,606 drugs checked — show the list

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

Showing the 60 most looked-up of 2,606 medications checked with no known interaction — see the full Inositol Nicotinate list.

See the full Inositol Nicotinate interactions page
See every supplement checked against Valacyclovir, ranked by severity
Evidence & sources

Inositol Nicotinate References

The 21 references that drive our Inositol Nicotinate 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. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
  2. Holti G. An experimentally controlled evaluation of the effect of inositol nicotinate upon the digital blood flow in patients with Raynaud's phenomenon. J Int Med Res 1979;7:473-83. PubMed
  3. Knodel LC, Talbert RL. Adverse effects of hypolipidaemic drugs. Med Toxicol 1987;2:10-32. PubMed
  4. Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
  5. Crouse JR III. New developments in the use of niacin for treatment of hyperlipidemia: new considerations in the use of an old drug. Coron Artery Dis 1996;7:321-6. PubMed
  6. Garg A, Grundy SM. Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990;264:723-6. DOI
  7. American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
  8. Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82:737-43.
  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  10. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  11. Bays HE, Dujovne CA. Drug interactions of lipid-altering drugs. Drug Saf 1998;19:355-71. PubMed
  12. Figge HL, Figge J, Souney PF, et al. Nicotinic acid: a review of its clinical use in the treatment of lipid disorders. Pharmacotherapy 1988;8:287-94. PubMed
  13. McKenney J. New perspectives on the use of niacin in the treatment of lipid disorders. Arch Intern Med 2004;164:697-705. PubMed
  14. Reaven P, Witztum JL. Lovastatin, nicotinic acid and rhabdomyolysis (letter). Ann Int Med 1988;109:597-8. PubMed
  15. Ito MK. Advances in the understanding and management of dyslipidemia: using niacin-based therapies. Am J Health-Syst Pharm 2003;60(suppl 2):s15-21. PubMed

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 Inositol Nicotinate and Valacyclovir Together: Common Questions

Is it safe to take Inositol Nicotinate with Valacyclovir?
We do not list a known interaction between Inositol Nicotinate and Valacyclovir. 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 Inositol Nicotinate and Valacyclovir have any of the same side effects?
Yes — our sources link each of them separately to 6 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 Inositol Nicotinate and Valacyclovir combination checked?
Interactions in our licensed database are recorded against drug classes. Valacyclovir is filed under 3 classifications, and Inositol Nicotinate has documented interactions with 4 drug classes — none of Valacyclovir'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 Inositol Nicotinate interact with any other medications?
Yes. Inositol Nicotinate has 223 documented drug interactions in our database — Valacyclovir 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 Valacyclovir interact with any supplements?
Yes. Valacyclovir has documented interactions with 27 supplements in our database — Inositol Nicotinate is not one of them. The Valacyclovir 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

Inositol Nicotinate monograph Uses, safety profile, and every drug interaction in one place Valacyclovir drug information The full plain-English guide to this medication Valacyclovir supplement interactions Every supplement checked against Valacyclovir, 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 21 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Valacyclovir and Inositol Nicotinate?

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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.