Drug & supplement interaction

Polydextrose + Phendimetrazine

Phendimetrazine brand names: Plegine, Metra, Weightrol.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Polydextrose and Phendimetrazine 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

Polydextrose and Phendimetrazine

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 Phendimetrazine and Polydextrose 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 Polydextrose at all — not against Phendimetrazine, 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.

Polydextrose safety at a glance

Polydextrose overall Generally safe Generally recognized as safe in foods for most people when consumed in normal amounts.
Pregnancy Use caution Amounts found in foods are likely fine, but check with your doctor before using supplement-level doses.
Breastfeeding Use caution Food amounts are likely fine, but data on concentrated supplement doses are limited.

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

Still wondering about combining Phendimetrazine and Polydextrose? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Polydextrose and Phendimetrazine 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.

  • Constipation Additional detail

    Polydextrose

    “Orally, polydextrose may cause gas, bloating, and loose stools. These adverse effects are more common when single doses of more than 50 grams or daily doses of more than 90 grams are used. Higher doses of polydextrose (90 grams/day or more) may also cause transient diarrhea in some people.”

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

    5 sources cited
    1. 27194. Burdock GA, Flamm WG. A review of the studies of the safety of polydextrose in food. Food Chem Toxicol 1999;37(2-3):233-264. PubMed
    2. 27208. Saku K, Yoshinaga K, Okura Y, et al. Effects of polydextrose on serum lipids, lipoproteins, and apolipoproteins in healthy subjects. Clin Ther 1991;13(2):254-258.
    3. 27212. Tomlin J, Read NW. A comparative study of the effects on colon function caused by feeding ispaghula husk and polydextrose. Aliment Pharmacol Ther 1988;2(6):513-519. PubMed
    4. 27193. Flood MT, Auerbach MH, Craig SA. A review of the clinical toleration studies of polydextrose in food. Food Chem Toxicol 2004;42(9):1531-1542. PubMed
    5. 106527. Colombo J, Carlson SE, Algarín C, et al. Developmental effects on sleep-wake patterns in infants receiving a cow's milk-based infant formula with an added prebiotic blend: a randomized controlled trial. Pediatr Res 2021;89(5):1222-31. PubMed

    Phendimetrazine

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

  • Dizziness Additional detail

    Polydextrose

    “Orally, one participant in one clinical study complained of transient dizziness after eating yogurt containing polydextrose 12.5 grams.”

    Polydextrose · Natural Medicines adverse-effect record, reported in vertigo.

    1 source cited
    1. 98660. Ibarra A, Olli K, Pasman W, et al. Effects of polydextrose with breakfast or with a midmorning preload on food intake and other appetite-related parameters in healthy normal-weight and overweight females: An acute, randomized, double-blind, placebo-contro

    Phendimetrazine

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

  • Diarrhea Additional detail

    Polydextrose

    “Orally, polydextrose seems to be well tolerated when used in doses of less than 50 grams.

    Most Common Adverse Effects:

    Orally: Bloating, diarrhea, gas.”

    Polydextrose · Natural Medicines adverse-effect record, reported in diarrhea.

    Phendimetrazine

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

Reported for Polydextrose but not commonly for Phendimetrazine: a skin rash and bloating or gas.

Effects for Phendimetrazine come from the ADVERSE REACTIONS section of its FDA label; effects for Polydextrose 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.

Overlapping uses

What Phendimetrazine Is Prescribed For, and What Polydextrose Has Been Studied For

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

Phendimetrazine is prescribed for: Phendimetrazine tartrate is used to help manage exogenous obesity (excess body weight from outside causes like diet and lifestyle) as a short-term addition to a calorie-restricted diet. It is intended for adults with a BMI of 30 or higher, or a BMI of 27 or higher when other risk factors — such as high blood pressure, diabetes, or high cholesterol — are also present. It is approved for use as monotherapy only, meaning it must not be combined with other weight-loss drugs or stimulants. Both the tablet form and the extended-release capsule form are approved for this purpose.

Read the rest of what Phendimetrazine is prescribed for

This medication is meant to be used for only a few weeks as part of a broader weight-management plan.

Polydextrose has been studied for:

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

    Polydextrose for diabetes

    It is unclear if oral polydextrose is beneficial in patients with diabetes.

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

    Polydextrose for obesity

    Polydextrose has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

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 Phendimetrazine on your own; if you are taking Polydextrose for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Phendimetrazine

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

“Of the 17 supplements on file for phendimetrazine, an appetite-suppressant stimulant prescribed short term for weight loss, activated charcoal is the one that demands real caution. Charcoal binds medications in the gut and can sharply cut how much of a drug your body absorbs, leaving you with less appetite control than your prescriptio…”

Reviewed by 2 · Jul 18, 2026

Open the Phendimetrazine interaction page

One more smart check

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

We hold 37 real supplement products containing Polydextrose, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Polydextrose. Even though Polydextrose itself has no known interaction with Phendimetrazine, 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 Polydextrose and Phendimetrazine 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 Polydextrose
Top half

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

29 days ago today
Medication Phendimetrazine
Top 25%

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

What is Polydextrose?

  • Adding dietary fiber
  • Supporting digestive regularity
  • Sugar and fat replacement in foods
  • Promoting gut bacteria (prebiotic)
  • Helping with calorie reduction

Polydextrose is a man-made soluble fiber used widely in foods as a low-calorie bulking agent and prebiotic. It is generally well tolerated, though large amounts can cause gas, bloating, or loose stools. It is not a medicine and should not replace a balanced, fiber-rich diet.

Synthetic carbohydrate made from glucose (dextrose), sorbitol, and citric acid · Added to foods and drinks (baked goods, low-calorie products), powders, fiber supplements

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

Polydextrose: dosing

There is no official medicinal dose for polydextrose, since it is mainly used as a food ingredient rather than a medicine. The amount you get depends on the foods or supplements you choose.If you use a product that contains polydextrose, follow the directions on the label. As with any fiber, it is best to start with a small amount and increase gradually while drinking plenty of water.

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

Read the full Polydextrose monograph & all interactions
Medication

About Phendimetrazine

What Is Phendimetrazine Used For?

Brand names: Plegine, Metra, Weightrol

Phendimetrazine tartrate is used to help manage exogenous obesity (excess body weight from outside causes like diet and lifestyle) as a short-term addition to a calorie-restricted diet. It is intended for adults with a BMI of 30 or higher, or a BMI of 27 or higher when other risk factors — such as high blood pressure, diabetes, or high cholesterol — are also present.

It is approved for use as monotherapy only, meaning it must not be combined with other weight-loss drugs or stimulants. Both the tablet form and the extended-release capsule form are approved for this purpose. This medication is meant to be used for only a few weeks as part of a broader weight-management plan.

See full Phendimetrazine drug information
Keep checking

Other Drugs & Polydextrose

Browse every other medication we’ve checked against Polydextrose — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Polydextrose References

The 7 references that drive our Polydextrose 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. Ziegler E, Vanderhoof JA, Petschow B, et al. Term infants fed formula supplemented with selected blends of prebiotics grow normally and have soft stools similar to those reported for breast-fed infants. J Pediatr Gastroenterol Nutr 2007;44(3):359-364. PubMed
  2. Flood MT, Auerbach MH, Craig SA. A review of the clinical toleration studies of polydextrose in food. Food Chem Toxicol 2004;42(9):1531-1542. PubMed
  3. Burdock GA, Flamm WG. A review of the studies of the safety of polydextrose in food. Food Chem Toxicol 1999;37(2-3):233-264. PubMed
  4. Saku K, Yoshinaga K, Okura Y, et al. Effects of polydextrose on serum lipids, lipoproteins, and apolipoproteins in healthy subjects. Clin Ther 1991;13(2):254-258.
  5. Tomlin J, Read NW. A comparative study of the effects on colon function caused by feeding ispaghula husk and polydextrose. Aliment Pharmacol Ther 1988;2(6):513-519. PubMed
  6. Ibarra A, Olli K, Pasman W, et al. Effects of polydextrose with breakfast or with a midmorning preload on food intake and other appetite-related parameters in healthy normal-weight and overweight females: An acute, randomized, double-blind, placebo-contro
  7. Colombo J, Carlson SE, Algarín C, et al. Developmental effects on sleep-wake patterns in infants receiving a cow's milk-based infant formula with an added prebiotic blend: a randomized controlled trial. Pediatr Res 2021;89(5):1222-31. 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 Polydextrose and Phendimetrazine Together: Common Questions

Is it safe to take Polydextrose with Phendimetrazine?
We do not list a known interaction between Polydextrose and Phendimetrazine. 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 Polydextrose and Phendimetrazine have any of the same side effects?
Yes — our sources link each of them separately to 3 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.
Are Polydextrose and Phendimetrazine 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 Polydextrose in each. That is a conversation for your prescriber, especially if Phendimetrazine is being adjusted to a target.
Does Phendimetrazine interact with any supplements?
Yes. Phendimetrazine has documented interactions with 17 supplements in our database — Polydextrose is not one of them. The Phendimetrazine interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Phendimetrazine and Polydextrose?

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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.