Medication interaction hub

What Supplements Interact with Phentermine?

Phentermine brand names: Adipex-P, Fastin, T Diet, Phentride, Obenix, and others. Every interaction below applies to the brands too.

61 Interactions 5 Major 43 Moderate 13 Minor
Curated & coded by · Clinical Pharmacist · Updated September 24, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Phentermine? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Phentermine against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

Ephedra is the pairing I most want anyone taking phentermine (Adipex-P) to know about. Phentermine is itself a stimulant appetite suppressant that raises heart rate and blood pressure, and ephedra piles the same cardiovascular strain on top of it. That stacking pattern covers 44 of the 61 ingredients on file here, and with five rated major, this list calls for real vigilance. Even everyday caffeine, from coffee, tea, or cocoa, lands in the moderate group for the same reason.

The other 17 entries change how much of an oral dose gets absorbed. Activated charcoal is the sharpest example, rated major because it binds phentermine in the gut and cuts what reaches your bloodstream, and bulky weight-loss fibers carry a similar concern. Alongside the five major warnings sit 43 moderate and 13 minor entries. If you use charcoal or a fiber product, take it well away from your phentermine dose.

— , Clinical Pharmacist · July 18, 2026

Major 5 Moderate 43 Minor 13 No known interaction 1,391

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Most Viewed Ingredient Interactions

Phentermine: Top Interactions at a Glance

The Phentermine supplement & herbal interactions people checked most in the last 24 hours, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 61 interacting ingredients — plus 1,391 more checked with no known interaction. See the complete ranked list.

Start here

The Most-Checked Phentermine Combinations Today

The Phentermine + supplement pages people viewed most in the last 24 hours (resets at midnight). Open any card for the full report.

Moderate Likelihood Probable Black Tea + Phenterminei

Theoretically, concomitant use might increase stimulant adverse effects.

Read the full interaction Moderate Likelihood Probable Caffeine + Phenterminei

Theoretically, concomitant use might increase stimulant adverse effects.

Read the full interaction Moderate Likelihood Possible Guarana + Phenterminei

Theoretically, concomitant use might increase stimulant adverse effects.

Read the full interaction Minor Likelihood Possible Blond Psyllium + Phenterminei

Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.

Read the full interaction Moderate Likelihood Probable Cocoa + Phenterminei

Theoretically, concomitant use might increase stimulant adverse effects.

Read the full interaction Major Likelihood Probable Activated Charcoal + Phenterminei

Activated charcoal reduces systemic exposure to many drugs, including those that undergo enterohepatic recirculation, regardless of the route of administration.

Read the full interaction
The complete list

Every Supplement Checked Against Phentermine

All 1,452 ingredients in our database, ranked by severity — 61 with a Phentermine interaction on file and 1,391 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Phentermine?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Black Tea with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Black Tea + Phentermine answer

Can you take Caffeine with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Caffeine + Phentermine answer

Can you take Guarana with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Guarana + Phentermine answer

Can you take Blond Psyllium with Phentermine?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, psyllium might increase, decrease, or have no effect on the absorption of oral drugs.

Full Blond Psyllium + Phentermine answer

Can you take Cocoa with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Cocoa + Phentermine answer

Can you take Oolong Tea with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Oolong Tea + Phentermine answer

Can you take Psilocybin with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of psilocybin with stimulant drugs might increase stimulant adverse effects.

Full Psilocybin + Phentermine answer

Can you take Pu-erh Tea with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase stimulant adverse effects.

Full Pu-erh Tea + Phentermine answer

Can you take Yerba Mate with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of stimulant drugs and yerba mate might increase stimulant adverse effects.

Full Yerba Mate + Phentermine answer

Can you take 1,3-dmaa with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. 1,3-DMAA is thought to have stimulant effects.

Full 1,3-dmaa + Phentermine answer

Can you take 1,3-dmba with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, combining 1,3-DMBA with other stimulant drugs might increase the risk of cardiovascular toxicity.

Full 1,3-dmba + Phentermine answer

Can you take 1,4-dmaa with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. 1,4-DMAA is thought to have stimulant and vasoconstrictive effects, which have been demonstrated in animal studies.

Full 1,4-dmaa + Phentermine answer

Can you take Acacia Rigidula with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking Acacia rigidula with stimulant drugs might increase the risk of adverse cardiovascular effects.

Full Acacia Rigidula + Phentermine answer

Can you take Aconite with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, combining aconite with other stimulant drugs might alter the effects of the stimulant drug or increase the risk of cardiovasc...

Full Aconite + Phentermine answer

Can you take Adrafinil with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking adrafinil with stimulant drugs might have additive stimulant effects.

Full Adrafinil + Phentermine answer

Can you take Beta-methylphenethylamine (bmpea) with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking BMPEA with other stimulant drugs might increase the risk of adverse cardiovascular effects.

Full Beta-methylphenethylamine (bmpea) + Phentermine answer

Can you take Bitter Orange with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, bitter orange might increase the risk of hypertension and adverse cardiovascular effects when taken with stimulant drugs.

Full Bitter Orange + Phentermine answer

Can you take Dimethylhexylamine (dmha) with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, combining DMHA with stimulant drugs might increase the risk of adverse cardiovascular effects.

Full Dimethylhexylamine (dmha) + Phentermine answer

Can you take Ergot with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Co-administration of stimulant drugs with ergot may increase the risk of vasoconstriction.

Full Ergot + Phentermine answer

Can you take Guar Gum with Phentermine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Guar gum might reduce the absorption of some oral drugs, potentially decreasing their effectiveness.

Full Guar Gum + Phentermine answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Phentermine is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Phentermine, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Phentermine sits in 2 interaction categories. Open any one to see what the group means:

Stimulant Drugs 44 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

44 of the supplement ingredients on this page reach Phentermine through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Phentermine through this category.

About Phentermine

Phentermine is an appetite-suppressing medication used short-term to help overweight people lose weight while dieting and exercising.

Generic name: Phentermine  ·  Brand names: Adipex-P, Fastin, T Diet, Phentride, Obenix, Pbc Phentride, Pbw Phentride, Phentrol #3, Ionamin, Phentrol #6, Phentrol #2, Phentrol #5, Phentrol, Obermine, Phentermine, Suprenza.

See the full Phentermine drug information
Check a real product

Take a Supplement Product? Check the Whole Bottle Against Phentermine

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Phentermine.

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Pharmacist Counseling Corner

Phentermine & Supplements: Common Questions

What supplements interact with Phentermine?
More than you might expect — 61 in total, though they are far from equal: 5 are rated major, 43 moderate, and 13 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: Activated Charcoal, Ephedra, Peyote.
Which Phentermine supplement interactions are the most serious?
The 5 major-rated combinations — led by Activated Charcoal, Ephedra, Peyote, Rauvolfia Vomitoria and Sida Cordifolia — deserve real caution: these are the ones generally best avoided, or used only with your prescriber watching. If you take any of them today, don't panic and don't stop anything abruptly — call your pharmacist first. Jump to the ranked list.
Can I take vitamins or supplements while on Phentermine?
Usually yes — most people on Phentermine can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like Adipex-P have the same supplement interactions as Phentermine?
Yes — Adipex-P, Fastin, T Diet, Phentride, Obenix and other brands all contain Phentermine, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Phentermine and my other medications?
This page covers Phentermine against supplements and herbal ingredients. Checking Phentermine against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker, or read the full Phentermine drug information.

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

Where next

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 24, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.