Drug & supplement interaction

Bitter Yam + Colesevelam

Colesevelam brand names: WelChol, Lodalis.

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 Bitter Yam and Colesevelam 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 label for Colesevelam states a food rule worth keeping to.

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Interaction report

Bitter Yam and Colesevelam

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 Colesevelam and Bitter Yam 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.

Bitter Yam safety at a glance

Bitter Yam overall Use caution Human safety data are limited, and improperly prepared bitter yam can be toxic.
Pregnancy Avoid Not enough safety information exists, so it is best avoided during pregnancy.
Breastfeeding Avoid There is no reliable safety data, so avoid use while breastfeeding.

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

Still wondering about combining Colesevelam and Bitter Yam? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Colesevelam

Interactions in our licensed database are recorded against drug classes, not just single drug names. Colesevelam is filed under a single classification — oral drugs. Bitter Yam has documented interactions with 1 drug class — the most serious being digoxin (lanoxin) (moderate) — and none of Colesevelam’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

Bitter Yam Does Interact With Other Medications

Bitter Yam has 1 moderate known drug interaction in our database — Colesevelam isn’t one of them. If you take anything else, check it against the full list below.

Moderate 1 No known interaction 2,829 (incl. Colesevelam)
Taking anything else?

Check Another of Your Medications Against Bitter Yam

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

What to actually watch for

What Colesevelam’s Own FDA Label Lists

This is not an interaction — none of it involves Bitter Yam. These are the most notable effects listed in the ADVERSE REACTIONS section of Colesevelam’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. 10 of them are worth acting on rather than waiting out — marked below.

  • A bowel blockage Worth acting on
  • Trouble swallowing Worth acting on
  • Low blood sugar Worth acting on
  • A slow heartbeat Worth acting on
  • A heart attack Worth acting on
  • Pancreatitis Worth acting on
  • High blood sugar Worth acting on
  • Seizures Worth acting on
  • Raised blood pressure Worth acting on
  • A higher chance of infection Worth acting on

Showing the 10 most notable of 24 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Colesevelam. Read the label on DailyMed › Where a percentage is shown, it is the share of 2,014 voluntary FDA FAERS reports for Colesevelam that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Bitter Yam’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Bitter Yam side to compare — that is a limit of the record, not a statement that Bitter Yam has no side effects.

How to take them

Some Colesevelam Products Have a Food Rule — Bitter Yam Should Not Break It

At least one FDA label for a product containing Colesevelam says to take it with food. If you take Bitter Yam on an empty stomach out of habit, keep them separate — and take Colesevelam with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Colesevelam products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Colesevelam hydrochloride should be taken as follows ( 2.2 , 2.4 ): Tablets Take 6 tablets once daily or 3 tablets twice daily with a meal and liquid.

From the Dosage and Administration section of the FDA label we read for Colesevelam — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Colesevelam Is Prescribed For, and What Bitter Yam Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Colesevelam is a prescription medicine with approved uses on its FDA label. Bitter Yam is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Colesevelam is prescribed for: Colesevelam is used alongside diet and exercise to reduce high LDL cholesterol (the "bad" cholesterol) in adults with primary hyperlipidemia (high cholesterol). It is also approved to lower LDL cholesterol in boys and girls aged 10–17 who have heterozygous familial hypercholesterolemia (HeFH) — an inherited condition that causes very high cholesterol — when diet and lifestyle changes alone haven't worked. Colesevelam tablets and oral suspension (Welchol and colesevelam hydrochloride products) are also used to improve blood sugar control in adults with type 2 diabetes, as an add-on to diet and exercise. Colesevelam is not for type 1 diabetes or diabetic ketoacidosis.

Bitter Yam has been studied for:

  • Diabetes studied, not established Bitter Yam has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Bitter Yam for diabetes

    Although there has been interest in using oral bitter yam for diabetes, there is insufficient reliable information about the clinical effects of bitter yam for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Colesevelam on your own; if you are taking Bitter Yam for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Bitter Yam or Colesevelam

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

This page covers Bitter Yam only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colesevelam 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 Colesevelam page

“Colesevelam (WelChol, Lodalis) lowers cholesterol by binding bile acids in your gut, and every one of the 17 supplements on this list can interfere with how oral medicines are absorbed in that same territory. I would treat this list with genuine care, and the place to start is activated charcoal, the only major-rated entry.”

Reviewed by 2 · Jul 18, 2026

Open the Colesevelam interaction page

How much people look this up

Where Bitter Yam and Colesevelam 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 Bitter Yam
Top half

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

29 days ago today
Medication Colesevelam
Steady interest

#1,744 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 Bitter Yam reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Bitter Yam and Colesevelam records this page draws on were last updated July 11, 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 Bitter Yam

What is Bitter Yam?

Bitter Yam
  • Blood sugar support
  • Digestive complaints
  • Traditional food source
  • Wound and skin care (folk use)

Bitter yam is a wild African yam used traditionally as both food and folk medicine, often for blood sugar and digestion. Scientific evidence in humans is very limited, and some bitter yam species can be toxic if not properly prepared. Talk to a pharmacist or doctor before using it as a supplement.

Dioscorea dumetorum · Dioscoreaceae · Tuber (root) · Cooked tuber, dried powder, traditional preparations

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

Bitter Yam: dosing

There is no established, standardized dose of bitter yam as a supplement. Traditional use varies widely and depends on how the tuber is prepared.If you choose to use a commercial product, follow the directions on the label and do not take more than recommended.

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

Read the full Bitter Yam monograph & all interactions
Medication

About Colesevelam

What Is Colesevelam Used For?

Brand names: WelChol, Lodalis

Colesevelam is used alongside diet and exercise to reduce high LDL cholesterol (the "bad" cholesterol) in adults with primary hyperlipidemia (high cholesterol). It is also approved to lower LDL cholesterol in boys and girls aged 10–17 who have heterozygous familial hypercholesterolemia (HeFH) — an inherited condition that causes very high cholesterol — when diet and lifestyle changes alone haven't worked.

Colesevelam tablets and oral suspension (Welchol and colesevelam hydrochloride products) are also used to improve blood sugar control in adults with type 2 diabetes, as an add-on to diet and exercise. Colesevelam is not for type 1 diabetes or diabetic ketoacidosis.

Most-Reported Side Effects for Colesevelam

From FAERS, the FDA’s public side-effect reporting system (2,014 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 241 reports
Dyspnea 172 reports
Cough 169 reports
Muscle spasms 163 reports
Nasopharyngitis 150 reports
See full Colesevelam drug information
Keep checking

Other Drugs & Bitter Yam

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

0Major
1Moderate
0Minor
2,828No known interaction
1 Moderate 2,828 No interaction
Moderate

1 interaction

No interaction 2,828 drugs checked — show the list

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

Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Bitter Yam list.

See the full Bitter Yam interactions page
See every supplement checked against Colesevelam, ranked by severity
Evidence & sources

Bitter Yam References

The 1 references that drive our Bitter Yam 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. Nimenibo-Uadia R. Control of hyperlipidaemia, hypercholesterolaemia and hyperketonaemia by aqueous extract of Dioscorea dumetorum tuber. Trop J Pharm Res 2003;2:183-9. Available at: http://www.bioline.org.br/request?pr03009. DOI

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 Bitter Yam and Colesevelam Together: Common Questions

Is it safe to take Bitter Yam with Colesevelam?
We do not list a known interaction between Bitter Yam and Colesevelam. 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.
Should I take Bitter Yam and Colesevelam at the same time of day?
At least one FDA label for a product containing Colesevelam says to take it with food. If you take Bitter Yam on an empty stomach out of habit, keep them separate and take Colesevelam with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Colesevelam products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Are Bitter Yam and Colesevelam used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Bitter Yam in each. That is a conversation for your prescriber, especially if Colesevelam is being adjusted to a target.
How was the Bitter Yam and Colesevelam combination checked?
Interactions in our licensed database are recorded against drug classes. Colesevelam is filed under 1 classification, and Bitter Yam has documented interactions with 1 drug class — none of Colesevelam'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 Bitter Yam interact with any other medications?
Yes. Bitter Yam has 1 documented drug interaction in our database — Colesevelam 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 Colesevelam interact with any supplements?
Yes. Colesevelam has documented interactions with 17 supplements in our database — Bitter Yam is not one of them. The Colesevelam 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

Bitter Yam monograph Uses, safety profile, and every drug interaction in one place Colesevelam drug information The full plain-English guide to this medication Colesevelam supplement interactions Every supplement checked against Colesevelam, 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 Colesevelam and Bitter Yam?

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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.