Drug & supplement interaction

Hydroxymethylbutyrate (hmb) + Psyllium (OTC drug)

Psyllium (OTC drug) brand name: Metamucil.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug) 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.

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Interaction report

Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug)

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 Psyllium (OTC drug) and Hydroxymethylbutyrate (hmb) 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Hydroxymethylbutyrate (hmb) at all — not against Psyllium (OTC drug), and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Hydroxymethylbutyrate (hmb) safety at a glance

Hydroxymethylbutyr... overall Use caution Generally well tolerated in healthy adults for short-term use, but long-term safety is not well studied.
Pregnancy Avoid Not enough safety data exists, so it is best avoided during pregnancy.
Breastfeeding Avoid There is no reliable safety information, so avoid use while breastfeeding.

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

Still wondering about combining Psyllium (OTC drug) and Hydroxymethylbutyrate (hmb)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Hydroxymethylbutyrate (hmb) Itself Has Been Linked To

This is not an interaction — nothing below involves Psyllium (OTC drug). It is the side-effect record for Hydroxymethylbutyrate (hmb) on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Hydroxymethylbutyrate (hmb), this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Raised blood pressure Worth acting on Additional detail

    “Orally, high blood pressure has been reported in one person taking HMB in a clinical trial.”

    Hydroxymethylbutyrate (hmb) · Natural Medicines adverse-effect record, reported in hypertension.

    1 source cited
    1. 108770. Osuka Y, Kojima N, Sasai H, et al. Effects of exercise and/or ß-hydroxy-ß-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in older women with low muscle mass: a randomized, double-blind, placebo-controlled trial. A PubMed
  • Heartburn / Bloating or gas / Stomach upset / Constipation / Stomach pain / Nausea Additional detail

    “Orally, abdominal pain, constipation, dyspepsia, flatulence, heartburn, and nausea have been reported rarely in people taking HMB in clinical trials.”

    Hydroxymethylbutyrate (hmb) · Natural Medicines adverse-effect record, reported in constipation.

    3 sources cited
    1. 99245. Berton L, Bano G, Carraro S, et al. Effect of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on physical performance in healthy old women over 65 years: An open label randomized controlled trial. PLoS One. 2015;10(11):e0141757. PubMed
    2. 102872. Tritto AC, Bueno S, Rodrigues RMP, Gualano B, Roschel H, Artioli GG. Negligible effects of ß-hydroxy-ß-methylbutyrate free acid and calcium salt on strength and hypertrophic responses to resistance training: a randomized, placebo-controlled study. Int J S PubMed
    3. 108770. Osuka Y, Kojima N, Sasai H, et al. Effects of exercise and/or ß-hydroxy-ß-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in older women with low muscle mass: a randomized, double-blind, placebo-controlled trial. A PubMed
  • Itching Additional detail

    “Orally, itching has been reported in two people taking HMB in clinical trials.”

    Hydroxymethylbutyrate (hmb) · Natural Medicines adverse-effect record, reported in pruritus.

    2 sources cited
    1. 99245. Berton L, Bano G, Carraro S, et al. Effect of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on physical performance in healthy old women over 65 years: An open label randomized controlled trial. PLoS One. 2015;10(11):e0141757. PubMed
    2. 102872. Tritto AC, Bueno S, Rodrigues RMP, Gualano B, Roschel H, Artioli GG. Negligible effects of ß-hydroxy-ß-methylbutyrate free acid and calcium salt on strength and hypertrophic responses to resistance training: a randomized, placebo-controlled study. Int J S PubMed

Everything above comes from the Natural Medicines adverse-effect record for Hydroxymethylbutyrate (hmb) — expand a row for the licensed statement it rests on. We haven’t matched Psyllium (OTC drug) to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Psyllium (OTC drug).

From our Q&A

Questions About Hydroxymethylbutyrate (hmb) or Psyllium (OTC drug)

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Hydroxymethylbutyrate (hmb) or Psyllium (OTC drug), 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 Psyllium (OTC drug)

This page covers Hydroxymethylbutyrate (hmb) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Psyllium (OTC drug) page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Psyllium (OTC drug) page

“Activated charcoal tops the psyllium (Metamucil) list and is the one entry rated major. Charcoal binds many medicines in the gut and can cut how much of them reaches the body, so pairing it with anything you take by mouth deserves real caution, and I would read that entry before the rest.”

Reviewed by 2 · Jul 18, 2026

Open the Psyllium (OTC drug) interaction page

How much people look this up

Where Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug) 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 Hydroxymethylbutyrate (hmb)
Steady interest

#1,221 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Psyllium (OTC drug)
Top 25%

#407 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 Hydroxymethylbutyrate (hmb) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug) 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 Hydroxymethylbutyrate (hmb)

What is Hydroxymethylbutyrate (hmb)?

  • Building or preserving muscle mass
  • Improving strength with resistance training
  • Reducing muscle breakdown
  • Supporting recovery after exercise
  • Preventing muscle loss in older adults or illness

HMB is a compound made in the body from the amino acid leucine and is sold as a supplement mainly to support muscle. The best evidence suggests it may help slow muscle loss in certain situations, such as during illness, bed rest, or aging, but results in healthy athletes are mixed. It appears generally well tolerated for most adults, but you should check with your pharmacist or doctor before starting it.

Not applicable (HMB is a metabolite of the amino acid leucine) · Capsules, tablets, powder, drink mixes; available as calcium-HMB (CaHMB) and free-acid HMB

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

Hydroxymethylbutyrate (hmb): dosing

There is no single official dose of HMB, and the best amount depends on the goal and the person. Most research has used HMB taken in divided doses across the day, often alongside resistance training or protein intake.The two common forms are calcium-HMB and free-acid HMB, which may be absorbed differently.

From our Hydroxymethylbutyrate (hmb) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Hydroxymethylbutyrate (hmb) monograph & all interactions
Medication

About Psyllium

What Is Psyllium Used For?

Brand name: Metamucil

Psyllium is used to treat occasional constipation and help restore regularity. It is available under many brand names — including Careone, Best Choice, Premier Value Fiber, fiber laxative, meijer fiber laxative, Publix, Best Choice Fiber Therapy, Daily Fiber, Dr. Fibra, Lidl Orange Smooth Fiber Powder, and meijer fiber therapy — all for this same purpose.

Most products note that psyllium generally produces a bowel movement within 12 to 72 hours of taking a dose.

See full Psyllium drug information
Keep checking

Other Drugs & Hydroxymethylbutyrate (hmb)

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Hydroxymethylbutyrate (hmb) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Hydroxymethylbutyrate (hmb) list.

See the full Hydroxymethylbutyrate (hmb) interactions page
See every supplement checked against Psyllium (OTC drug), ranked by severity
Evidence & sources

Hydroxymethylbutyrate (hmb) References

The 3 references that drive our Hydroxymethylbutyrate (hmb) 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. Berton L, Bano G, Carraro S, et al. Effect of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation on physical performance in healthy old women over 65 years: An open label randomized controlled trial. PLoS One. 2015;10(11):e0141757. PubMed
  2. Tritto AC, Bueno S, Rodrigues RMP, Gualano B, Roschel H, Artioli GG. Negligible effects of ß-hydroxy-ß-methylbutyrate free acid and calcium salt on strength and hypertrophic responses to resistance training: a randomized, placebo-controlled study. Int J S PubMed
  3. Osuka Y, Kojima N, Sasai H, et al. Effects of exercise and/or ß-hydroxy-ß-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in older women with low muscle mass: a randomized, double-blind, placebo-controlled trial. A 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 Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug) Together: Common Questions

Is it safe to take Hydroxymethylbutyrate (hmb) with Psyllium (OTC drug)?
We do not list a known interaction between Hydroxymethylbutyrate (hmb) and Psyllium (OTC drug). 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.
Does Psyllium (OTC drug) interact with any supplements?
Yes. Psyllium (OTC drug) has documented interactions with 17 supplements in our database — Hydroxymethylbutyrate (hmb) is not one of them. The Psyllium (OTC drug) 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

Hydroxymethylbutyrate (hmb) monograph Uses, safety profile, and every drug interaction in one place Psyllium drug information The full plain-English guide to this medication Psyllium (OTC drug) supplement interactions Every supplement checked against Psyllium (OTC drug), 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Psyllium (OTC drug) and Hydroxymethylbutyrate (hmb)?

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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.