Drug & supplement interaction

Tetrahydrocannabivarin (thcv) + Macitentan

Macitentan brand name: Opsumit.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Tetrahydrocannabivarin (thcv) and Macitentan 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

Tetrahydrocannabivarin (thcv) and Macitentan

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 Macitentan and Tetrahydrocannabivarin (thcv) 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 Tetrahydrocannabivarin (thcv) at all — not against Macitentan, 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.

Tetrahydrocannabivarin (thcv) safety at a glance

Tetrahydrocannabiv... overall Use caution Human safety data are limited, and product quality and legality vary a lot.
Pregnancy Avoid Cannabis-derived compounds are not considered safe in pregnancy.
Breastfeeding Avoid Cannabinoids can pass into breast milk, so avoid use while nursing.

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

Still wondering about combining Macitentan and Tetrahydrocannabivarin (thcv)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Macitentan’s Own FDA Label Lists

This is not an interaction — none of it involves Tetrahydrocannabivarin (thcv). These are the most notable effects listed in the ADVERSE REACTIONS section of Macitentan’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. 6 of them are worth acting on rather than waiting out — marked below.

  • Heart failure Worth acting on
  • Anemia Worth acting on
  • A severe allergic reaction Worth acting on
  • A higher chance of infection Worth acting on mentioned in 6.6% of FDA reports for Macitentan
  • Liver problems Worth acting on
  • An allergic reaction Worth acting on
  • Flushing
  • A stuffy or runny nose
  • Sore throat
  • Low blood pressure

Showing the 10 most notable of 14 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 Macitentan. Read the label on DailyMed › Where a percentage is shown, it is the share of 68,860 voluntary FDA FAERS reports for Macitentan that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Tetrahydrocannabivarin (thcv)’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Tetrahydrocannabivarin (thcv) side to compare — that is a limit of the record, not a statement that Tetrahydrocannabivarin (thcv) has no side effects.

Everything else you take

See Every Supplement That Interacts With Macitentan

This page covers Tetrahydrocannabivarin (thcv) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Macitentan page lists 253 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Beer (major) and Grapefruit (major).

By severity: 9 major · 205 moderate · 39 minor.

From our pharmacist’s overview on the Macitentan page

“If you take macitentan (Opsumit) for pulmonary arterial hypertension, study this page rather than skim it. It lists 253 supplement and herbal ingredients, nine rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Macitentan interaction page

How much people look this up

Where Tetrahydrocannabivarin (thcv) and Macitentan 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 Tetrahydrocannabivarin (thcv)
Steady interest

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

29 days ago today
Medication Macitentan
Top 25%

#598 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. Tetrahydrocannabivarin (thcv) 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 Tetrahydrocannabivarin (thcv) reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Tetrahydrocannabivarin (thcv) and Macitentan records this page draws on were last updated June 22, 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 Tetrahydrocannabivarin (thcv)

What is Tetrahydrocannabivarin (thcv)?

  • Appetite control and weight management
  • Blood sugar support
  • Energy and focus
  • General wellness

Tetrahydrocannabivarin (THCV) is a minor cannabinoid found in cannabis that is being studied for appetite, metabolism, and blood sugar, but human evidence is very limited. Product quality, legal status, and dosing vary widely, so talk with your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Cannabis sativa · Cannabaceae · Flowers and leaves of the cannabis plant (THCV is an extracted or isolated cannabinoid) · Oils, tinctures, capsules, gummies, vape products, and isolated extracts

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

Tetrahydrocannabivarin (thcv): dosing

There is no established standard dose for THCV. Research is too limited to recommend a specific milligram amount, and effects may even differ between low and high doses.If you choose to try a product, follow the directions on the label and start with the lowest amount.

From our Tetrahydrocannabivarin (thcv) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Tetrahydrocannabivarin (thcv) monograph & all interactions
Medication

About Macitentan

What Is Macitentan Used For?

Brand name: Opsumit

Macitentan tablets — sold under the brand name Opsumit — are used to treat pulmonary arterial hypertension (PAH, WHO Group I), a type of high blood pressure in the arteries of the lungs. The goal is to slow the disease from getting worse and to lower the chance of being hospitalized because of PAH.

In the key clinical study, macitentan was used in adults with mainly moderate-to-severe PAH symptoms. Patients had PAH caused by unknown or inherited causes, connective tissue disorders, or congenital heart disease with repaired shunts.

Most-Reported Side Effects for Macitentan

From FAERS, the FDA’s public side-effect reporting system (68,860 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 11,958 reports
Headache 8,323 reports
Diarrhea 6,584 reports
Nausea 5,972 reports
Fatigue 5,041 reports
See full Macitentan drug information
Keep checking

Other Drugs & Tetrahydrocannabivarin (thcv)

Browse every other medication we’ve checked against Tetrahydrocannabivarin (thcv) — 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

Tetrahydrocannabivarin (thcv) References

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

  1. Cannabis (Marijuana) and Cannabinoids: What You Need To Know — NIH NCCIH Source
  2. Marijuana — 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 Tetrahydrocannabivarin (thcv) and Macitentan Together: Common Questions

Is it safe to take Tetrahydrocannabivarin (thcv) with Macitentan?
We do not list a known interaction between Tetrahydrocannabivarin (thcv) and Macitentan. 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.
Does Macitentan interact with any supplements?
Yes. Macitentan has documented interactions with 253 supplements in our database — Tetrahydrocannabivarin (thcv) is not one of them. The Macitentan 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 Macitentan and Tetrahydrocannabivarin (thcv)?

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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.