Drug & supplement interaction

Reed Herb + Phentermine

Phentermine brand names: Adipex-P, Fastin, T Diet, Phentride, Obenix, and others.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Reed Herb and Phentermine 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

Reed Herb and Phentermine

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 Phentermine and Reed Herb 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 Reed Herb at all — not against Phentermine, 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.

Reed Herb safety at a glance

Reed Herb overall Use caution Traditionally used and generally well tolerated, but human safety data are limited.
Pregnancy Avoid Not enough safety information; best to avoid during pregnancy.
Breastfeeding Avoid No reliable safety data, so avoid while breastfeeding.

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

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

What Phentermine’s Own FDA Label Lists

This is not an interaction — none of it involves Reed Herb. These are the most notable effects listed in the ADVERSE REACTIONS section of Phentermine’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. 3 of them are worth acting on rather than waiting out — marked below.

  • Hallucinations Worth acting on
  • Raised blood pressure Worth acting on
  • Hives Worth acting on
  • Erection problems
  • Tremor or shakiness
  • A fast or pounding heartbeat
  • Anxiety or restlessness
  • Trouble sleeping
  • Stomach upset
  • Constipation

Showing the 10 most notable of 13 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 Phentermine. Read the label on DailyMed › Reed Herb’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Reed Herb side to compare — that is a limit of the record, not a statement that Reed Herb has no side effects.

Overlapping uses

What Phentermine Is Prescribed For, and What Reed Herb Has Been Studied For

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

Phentermine is prescribed for: Phentermine is approved as a short-term addition to a weight-loss program — not a standalone treatment. It is used alongside reduced-calorie eating, increased physical activity, and behavior changes to help manage obesity in adults whose body mass index (BMI) is 30 kg/m² or higher, or 27 kg/m² or higher when other risk factors such as controlled high blood pressure, diabetes, or high cholesterol (hyperlipidemia) are also present. All available phentermine products — including Adipex-P, Lomaira, and various generic capsules and tablets — share this same FDA-approved use. Lomaira tablets are specifically dosed to be taken three times daily before meals, while other formulations are generally taken once daily.

Read the rest of what Phentermine is prescribed for

Treatment is intended to last only a few weeks.

Reed Herb has been studied for:

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

    Reed Herb for diabetes

    Although there has been interest in using oral reed herb for diabetes, there is insufficient reliable information about the clinical effects of reed herb 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 Phentermine on your own; if you are taking Reed Herb for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Reed Herb or Phentermine

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

This page covers Reed Herb only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phentermine page lists 61 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Peyote (major), Rauvolfia Vomitoria (major) and Sida Cordifolia (major).

By severity: 5 major · 43 moderate · 13 minor.

From our pharmacist’s overview on the Phentermine page

“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.”

Reviewed by 2 · Jul 18, 2026

Open the Phentermine interaction page

One more smart check

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

We hold 57 real supplement products containing Reed Herb, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Reed Herb. Even though Reed Herb itself has no known interaction with Phentermine, 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 Reed Herb and Phentermine 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 Reed Herb
Steady interest

#1,102 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phentermine
Top 25%

#498 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. Reed Herb is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Reed Herb reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Reed Herb and Phentermine records this page draws on were last updated June 20, 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 Reed Herb

What is Reed Herb?

Reed Herb
  • Digestive upset
  • Nausea and vomiting
  • Diuretic (increasing urine)
  • Promoting sweating during fevers
  • Clearing heat (traditional use)

Reed herb (Phragmites australis) is a tall grass whose stems and roots have long been used in traditional medicine, especially for digestive complaints, fever, and as a mild diuretic. Modern scientific evidence in people is very limited, so its benefits are not well proven. If you want to try it, talk with a pharmacist or doctor first, and avoid it during pregnancy and breastfeeding due to a lack of safety data.

Phragmites australis · Poaceae · Stem and rhizome (root) · Tea, decoction, dried herb, powder

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

Reed Herb: dosing

There is no standardized, well-established dose for reed herb. Traditional preparations are usually made as a decoction or tea from the dried stem or rhizome, but the right amount can vary widely.If you choose to use a commercial product, follow the directions on the label and do not take more than recommended.

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

Read the full Reed Herb monograph & all interactions
Medication

About Phentermine

What Is Phentermine Used For?

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

Phentermine is approved as a short-term addition to a weight-loss program — not a standalone treatment. It is used alongside reduced-calorie eating, increased physical activity, and behavior changes to help manage obesity in adults whose body mass index (BMI) is 30 kg/m² or higher, or 27 kg/m² or higher when other risk factors such as controlled high blood pressure, diabetes, or high cholesterol (hyperlipidemia) are also present.

All available phentermine products — including Adipex-P, Lomaira, and various generic capsules and tablets — share this same FDA-approved use. Lomaira tablets are specifically dosed to be taken three times daily before meals, while other formulations are generally taken once daily. Treatment is intended to last only a few weeks.

See full Phentermine drug information
Keep checking

Other Drugs & Reed Herb

Browse every other medication we’ve checked against Reed Herb — 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

Reed Herb References

The 2 sources that drive our Reed Herb monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Reed Herb is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.

  1. Herbs at a Glance — NIH NCCIH Source
  2. Herbs and Supplements — MedlinePlus Source

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 Reed Herb and Phentermine Together: Common Questions

Is it safe to take Reed Herb with Phentermine?
We do not list a known interaction between Reed Herb and Phentermine. 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.
Are Reed Herb and Phentermine 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 Reed Herb in each. That is a conversation for your prescriber, especially if Phentermine is being adjusted to a target.
Does Phentermine interact with any supplements?
Yes. Phentermine has documented interactions with 61 supplements in our database — Reed Herb is not one of them. The Phentermine 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 Phentermine and Reed Herb?

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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.