Drug & supplement interaction

Sea Buckthorn + Trimethoprim

Trimethoprim brand names: Proloprim, Trimpex.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Sea Buckthorn and Trimethoprim 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

Sea Buckthorn and Trimethoprim

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 Trimethoprim and Sea Buckthorn 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.

Sea Buckthorn safety at a glance

Sea Buckthorn overall Use caution Generally well tolerated as a food, but supplement safety has not been fully studied.
Pregnancy Use caution Food amounts are likely fine, but supplement doses are not well studied, so use caution and ask your doctor.
Breastfeeding Use caution Not enough reliable safety data on supplement use while breastfeeding; use caution.

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

Still wondering about combining Trimethoprim and Sea Buckthorn? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Trimethoprim

Interactions in our licensed database are recorded against drug classes, not just single drug names. Trimethoprim is filed under 4 classifications — including qt interval-prolonging drugs, antibiotic drugs, oral drugs. Sea Buckthorn has documented interactions with 2 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate) and antihypertensive drugs (moderate) — and none of Trimethoprim’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

Sea Buckthorn Does Interact With Other Medications

Sea Buckthorn has 289 moderate known drug interactions in our database — Trimethoprim isn’t one of them. If you take anything else, check it against the full list below.

Moderate 289 No known interaction 2,541 (incl. Trimethoprim)
Taking anything else?

Check Another of Your Medications Against Sea Buckthorn

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

What to actually watch for

No Interaction Found — But Data Suggests Sea Buckthorn and Trimethoprim 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.

  • Itching / A skin rash reported in 5.3% of FDA reports for Trimethoprim Additional detail

    Sea Buckthorn

    “Orally, high doses of sea buckthorn may cause yellow staining of the skin. One case of generalized yellow skin has been reported for a patient who consumed sea buckthorn 100 grams daily for 6 months. Topically, sea buckthorn oil has been associated with dryness, irritation, redness, and rash. Rash occurred in 4% of patients in one clinical study.”

    Sea Buckthorn · Natural Medicines adverse-effect record, reported in pruritus.

    4 sources cited
    1. 74072. Grad, S. C., Muresan, I., and Dumitrascu, D. L. Generalized yellow skin caused by high intake of sea buckthorn. Forsch.Komplementmed. 2012;19(3):153-156. PubMed
    2. 74077. Vlasov, V. V. [Hippophae oil in the treatment of superficial skin burns]. Vestn.Dermatol Venerol. 1970;44(6):69-72.
    3. 102845. Larmo P, Järvinen R, Laihia J, et al. Effects of a sea buckthorn oil spray emulsion on dry eye. Cont Lens Anterior Eye. 2019;42(4):428-433. PubMed
    4. 106089. De Seta F, Caruso S, Di Lorenzo G, Romano F, Mirandola M, Nappi RE. Efficacy and safety of a new vaginal gel for the treatment of symptoms associated with vulvovaginal atrophy in postmenopausal women: A double-blind randomized placebo-controlled study. Ma PubMed

    Trimethoprim

    Listed in the ADVERSE REACTIONS section of the FDA label for Trimethoprim, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Effects for Trimethoprim come from the ADVERSE REACTIONS section of its FDA label; effects for Sea Buckthorn come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 93,588 voluntary FDA FAERS reports for Trimethoprim that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Sea Buckthorn or Trimethoprim

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

This page covers Sea Buckthorn only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Trimethoprim page lists 59 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 7 major · 41 moderate · 11 minor.

From our pharmacist’s overview on the Trimethoprim page

“Most prescriptions for trimethoprim are short courses for bladder infections, which makes it easy to assume nothing swallowed alongside it matters much. Seven of the 59 supplement and herbal ingredients here rate major, though, and nearly all of them involve heart rhythm: grapefruit in large amounts, ephedra, and a few others can prolo…”

Reviewed by 2 · Jul 18, 2026

Open the Trimethoprim interaction page

One more smart check

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

We hold 253 real supplement products containing Sea Buckthorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Sea Buckthorn. Even though Sea Buckthorn itself has no known interaction with Trimethoprim, 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 Sea Buckthorn and Trimethoprim 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 Sea Buckthorn
Top half

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

29 days ago today
Medication Trimethoprim
Steady interest

#1,444 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 Sea Buckthorn reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Sea Buckthorn and Trimethoprim 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 Sea Buckthorn

What is Sea Buckthorn?

Sea Buckthorn
  • Skin health and dryness
  • Dry eye symptoms
  • Digestive complaints
  • Heart and cholesterol support
  • General antioxidant and immune support

Sea buckthorn is a berry-bearing shrub rich in vitamins, carotenoids, and fatty acids that people use for skin, eye, digestive, and heart health. Early research is promising for a few uses like dry skin and dry eye, but most claims are not yet proven. It is generally well tolerated as a food, but talk to your pharmacist before using concentrated supplements.

Hippophae rhamnoides · Elaeagnaceae · Berries (fruit), seeds, seed and fruit oil, and sometimes leaves · Capsules, softgels, oil (seed or fruit), juice, powder, teas, topical creams and ointments

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

Sea Buckthorn: dosing

There is no official or standardized dose of sea buckthorn. The right amount depends on the product, its form (oil, capsule, juice, or powder), and how it is concentrated.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Sea Buckthorn monograph & all interactions
Medication

About Trimethoprim

What Is Trimethoprim Used For?

Brand names: Proloprim, Trimpex

Trimethoprim tablets are used to treat initial episodes of uncomplicated urinary tract infections (UTIs). It works against specific bacteria — including E. coli, Proteus mirabilis, Klebsiella pneumoniae, Enterobacter species, and coagulase-negative Staphylococcus species (including S. saprophyticus).

It should only be used when there is a proven or strongly suspected bacterial infection. Your doctor may order a urine culture to confirm which bacteria are present and whether trimethoprim will work against them.

Most-Reported Side Effects for Trimethoprim

From FAERS, the FDA’s public side-effect reporting system (95,001 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fever 6,904 reports
Fatigue 5,992 reports
Diarrhea 5,716 reports
Nausea 5,685 reports
Dyspnea 5,098 reports
See full Trimethoprim drug information
Keep checking

Other Drugs & Sea Buckthorn

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

0Major
289Moderate
0Minor
2,540No known interaction
289 Moderate 2,540 No interaction
Moderate

289 interactions

Showing 60 of 289 moderate interactions — see all 289 on the Sea Buckthorn page.

No interaction 2,540 drugs checked — show the list

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

Showing the 60 most looked-up of 2,540 medications checked with no known interaction — see the full Sea Buckthorn list.

See the full Sea Buckthorn interactions page
See every supplement checked against Trimethoprim, ranked by severity
Evidence & sources

Sea Buckthorn References

The 7 references that drive our Sea Buckthorn 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. Johansson AK, Korte H, Yang B, et al. Sea buckthorn berry oil inhibits platelet aggregation. J Nutr Biochem 2000;11:491-5.. PubMed
  2. Grad, S. C., Muresan, I., and Dumitrascu, D. L. Generalized yellow skin caused by high intake of sea buckthorn. Forsch.Komplementmed. 2012;19(3):153-156. PubMed
  3. Vlasov, V. V. [Hippophae oil in the treatment of superficial skin burns]. Vestn.Dermatol Venerol. 1970;44(6):69-72.
  4. Chang BB, Wang F Xu TY Zhang QQ He J Zhang XJ Li J. Total flavones of Hippophae rhamnoides L. for essential hypertension: a systematic review of randomized controlled trials. Chinese Journal of Evidence-Based Medicine. 2009;9(11):1207-1213. DOI
  5. Olas B, Kontek B, Szczesna M, et al. Inhibition of blood platelet adhesion by phenolics rich fraction of Hippophae rhamnoides L. fruits. J Physiol Pharmacol. 2017;68(2):223-9.
  6. Larmo P, Järvinen R, Laihia J, et al. Effects of a sea buckthorn oil spray emulsion on dry eye. Cont Lens Anterior Eye. 2019;42(4):428-433. PubMed
  7. De Seta F, Caruso S, Di Lorenzo G, Romano F, Mirandola M, Nappi RE. Efficacy and safety of a new vaginal gel for the treatment of symptoms associated with vulvovaginal atrophy in postmenopausal women: A double-blind randomized placebo-controlled study. Ma 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 Sea Buckthorn and Trimethoprim Together: Common Questions

Is it safe to take Sea Buckthorn with Trimethoprim?
We do not list a known interaction between Sea Buckthorn and Trimethoprim. 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 Sea Buckthorn and Trimethoprim have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
How was the Sea Buckthorn and Trimethoprim combination checked?
Interactions in our licensed database are recorded against drug classes. Trimethoprim is filed under 4 classifications, and Sea Buckthorn has documented interactions with 2 drug classes — none of Trimethoprim'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 Sea Buckthorn interact with any other medications?
Yes. Sea Buckthorn has 289 documented drug interactions in our database — Trimethoprim 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 Trimethoprim interact with any supplements?
Yes. Trimethoprim has documented interactions with 59 supplements in our database — Sea Buckthorn is not one of them. The Trimethoprim 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

Sea Buckthorn monograph Uses, safety profile, and every drug interaction in one place Trimethoprim drug information The full plain-English guide to this medication Trimethoprim supplement interactions Every supplement checked against Trimethoprim, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Trimethoprim and Sea Buckthorn?

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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.