Drug & supplement interaction

Gossypol + Theophylline

Theophylline brand names: T-Phyl, Duraphyl, Aerolate JR, Aerolate SR, Theo-Dur, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Gossypol has a moderate interaction with Theophylline. Theoretically, gossypol's male contraceptive effects might be reduced when taken with theophylline.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Gossypol and Theophylline

Here is the interaction we found between these two, with the evidence behind it.

Moderate

THEOPHYLLINE

Theoretically, gossypol's male contraceptive effects might be reduced when taken with theophylline.
In vitro research shows that theophylline interferes with the ability of gossypol to decrease sperm motility.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version of what we have on file: this isn't about theophylline becoming stronger or weaker. It's the other way around. The concern is that theophylline may blunt what gossypol is trying to do. Lab studies suggest theophylline can interfere with gossypol's ability to slow down sperm movement, so the contraceptive effect people were chasing with gossypol could be reduced.

I'll be honest with you though, this rests on test-tube research only, so it's pretty theoretical. The bigger picture is that gossypol isn't a safe or approved supplement to begin with (it carries risks like low potassium and organ toxicity), and theophylline itself needs careful dosing. Please don't experiment here. Talk with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Cowart CL, London SN, Vernon MW, Pedigo NG. The effects of cyclic adenosine monophosphate, forskolin, and theophylline on motility parameters in gossypol-treated human sperm. Fertil Steril 1994;61:929-34. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Gossypol Also Interacts With Other Medications

Gossypol has 103 moderate known drug interactions in our database — the Theophylline one above is one of them. If you take anything else, check it against the full list below.

Moderate 103 No known interaction 2,727 (incl. Theophylline)
Taking anything else?

Check Another of Your Medications Against Gossypol

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

From our Q&A

Questions About Gossypol or Theophylline

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

This page covers Gossypol only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Theophylline page lists 126 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Sida Cordifolia (major), Adrafinil (moderate) and African Wild Potato (moderate).

By severity: 3 major · 89 moderate · 34 minor.

From our pharmacist’s overview on the Theophylline page

“Stop ephedra before anything else if you take theophylline (Theo-Dur, Slo-Bid, and others) for asthma or COPD. Both are stimulants, and together they raise the risk of serious heart and nervous system effects; Sida cordifolia, an herb that contains ephedrine, carries the same major rating.”

Reviewed by 2 · Jul 18, 2026

Open the Theophylline interaction page

How much people look this up

Where Gossypol and Theophylline 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 Gossypol
Top 25%

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

29 days ago today
Medication Theophylline
Steady interest

#1,835 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.

Supplement

About Gossypol

What is Gossypol?

Gossypol
  • Male contraception (research interest)
  • Reduction of sperm production
  • Endometriosis (historical/research)
  • Antiviral and antiparasitic research
  • Cancer cell research

Gossypol is a toxic yellow pigment from cotton plants that has been studied mainly as an experimental male contraceptive because it can lower sperm production. It is not an approved or safe over-the-counter supplement, and it carries serious risks including possibly permanent infertility, low potassium, and organ toxicity. It should not be used for self-treatment.

Read the full Gossypol monograph & all interactions
Medication

About Theophylline

What Is Theophylline Used For?

Brand names: T-Phyl, Duraphyl, Aerolate JR, Aerolate SR, Theo-Dur, Slo-Bid, Theo-24, Uniphyl, Slo-phyllin Gyrocaps, Theolair, Theolair SR, Quibron-T/SR, Quibron-T, Aerolate III, Theo-X, Bronkodyl, Theoclear LA-130, Constant-T, Theoclear LA-260, Elixophyllin, Theovent, Theobid Jr Duracap, Respbid, Theobid Duracap

Theophylline — available as extended-release capsules (Theo-24), extended-release tablets, and oral solution (Elixophyllin) — is used to treat symptoms and reversible airflow obstruction caused by chronic asthma, emphysema, and chronic bronchitis.

All supported formulations share these indications. Theophylline is intended for patients with ongoing or recurring symptoms, not for sudden (acute) breathing attacks, which need faster-acting treatments.

See full Theophylline drug information
Keep checking

Other Drugs & Gossypol

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

0Major
103Moderate
0Minor
2,726No known interaction
103 Moderate 2,726 No interaction
Moderate

103 interactions

Showing 60 of 103 moderate interactions — see all 103 on the Gossypol page.

No interaction 2,726 drugs checked — show the list

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

Showing the 60 most looked-up of 2,726 medications checked with no known interaction — see the full Gossypol list.

See the full Gossypol interactions page
See every supplement checked against Theophylline, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Gossypol monograph › Uses, safety, and every drug interaction in one place Theophylline supplement interactions › Every supplement checked against Theophylline, ranked by severity Theophylline drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Gossypol and Theophylline Together: Common Questions

Can you take Gossypol with Theophylline?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Gossypol and Theophylline interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Theophylline and Gossypol?

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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.