Drug & supplement interaction

M1-4add + Crofelemer

Crofelemer brand names: Fulyzaq, Mytesi.

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

We found no known interaction between M1-4add and Crofelemer 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

M1-4add and Crofelemer

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 Crofelemer and M1-4add 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 M1-4add at all — not against Crofelemer, 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.

M1-4add safety at a glance

M1-4add overall Not established This product cannot be identified, so its safety is unknown.
Pregnancy Possibly Unsafe When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss... 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 Crofelemer and M1-4add? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Crofelemer’s Own FDA Label Lists

This is not an interaction — none of it involves M1-4add. These are the most notable effects listed in the ADVERSE REACTIONS section of Crofelemer’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 2 of them are worth acting on rather than waiting out — marked below.

  • Yellowing of the skin or eyes Worth acting on
  • A higher chance of infection Worth acting on
  • Bloating or gas
  • Back pain
  • Cough
  • Joint pain
  • Muscle pain
  • Nausea

From the ADVERSE REACTIONS section of the FDA label for Crofelemer. Read the label on DailyMed › Where a percentage is shown, it is the share of 233 voluntary FDA FAERS reports for Crofelemer that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. M1-4add’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no M1-4add side to compare — that is a limit of the record, not a statement that M1-4add has no side effects.

Special populations

M1-4add in Pregnancy & Breastfeeding

Pregnancy And Lactation Possibly Unsafe

When used orally. Prohormones can be converted to active hormones in the body and cause adverse effects such as menstrual irregularities, infertility, hair loss, and acne. Prohormones have also been associated with hepatotoxicity and increased risk of cardiovascular disease. The U.S. Food and Drug Administration and other regulatory agencies warn that dietary supplements containing prohormones are dangerous. Avoid using.

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

Everything else you take

See Every Supplement That Interacts With Crofelemer

This page covers M1-4add only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Crofelemer 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.

Open the Crofelemer interaction page

How much people look this up

Where M1-4add and Crofelemer 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 M1-4add
Steady interest

#1,218 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Crofelemer
Steady interest

#2,017 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 M1-4add reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The M1-4add and Crofelemer records this page draws on were last updated June 22, 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 M1-4add

What is M1-4add?

"M1-4add" does not match any recognized dietary supplement, herb, or botanical that we can confidently identify. Because we cannot verify what this product is, we cannot describe its uses, safety, or dosing. Please check the product label and ingredient list, and talk with a pharmacist or doctor before using anything with this name.

An interaction check asks whether these two react with each other — it does not ask whether M1-4add is a good idea for someone in your situation. Here is what our M1-4add record says about it on its own.

M1-4add: dosing

There is no established or recognized dose for M1-4add because the product cannot be identified. Never assume a higher dose is safer or more effective.

From our M1-4add monograph — the full record covers uses, side effects and every documented interaction.

Read the full M1-4add monograph & all interactions
Medication

About Crofelemer

What Is Crofelemer Used For?

Brand names: Fulyzaq, Mytesi

Mytesi (crofelemer) is approved to provide symptomatic relief of non-infectious diarrhea in adult patients with HIV/AIDS who are taking antiretroviral therapy.

It is not intended to treat diarrhea caused by an infection. Before starting Mytesi, a doctor will rule out infectious causes of diarrhea.

Most-Reported Side Effects for Crofelemer

From FAERS, the FDA’s public side-effect reporting system (233 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 26 reports
Anxiety 14 reports
Emotional distress 14 reports
Anhedonia 12 reports
Fatigue 11 reports
See full Crofelemer drug information
Keep checking

Other Drugs & M1-4add

Browse every other medication we’ve checked against M1-4add — 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 M1-4add 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 M1-4add list.

See the full M1-4add interactions page
See every supplement checked against Crofelemer, ranked by severity
Evidence & sources

M1-4add References

The 1 references that drive our M1-4add 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. Joseph JF, Parr MK. Synthetic androgens as designer supplements. Curr Neuropharmacol. 2015;13(1):89-100. 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 M1-4add and Crofelemer Together: Common Questions

Is it safe to take M1-4add with Crofelemer?
We do not list a known interaction between M1-4add and Crofelemer. 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 Crofelemer interact with any supplements?
Yes. Crofelemer has documented interactions with 17 supplements in our database — M1-4add is not one of them. The Crofelemer 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

M1-4add monograph Uses, safety profile, and every drug interaction in one place Crofelemer drug information The full plain-English guide to this medication Crofelemer supplement interactions Every supplement checked against Crofelemer, 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Crofelemer and M1-4add?

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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.