Drug & supplement interaction

Volumetrics Diet + Macitentan

Macitentan brand name: Opsumit.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Volumetrics Diet 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

Volumetrics Diet 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 Volumetrics Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Volumetrics Diet alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for Volumetrics Diet 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.

Volumetrics Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. 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.

Volumetrics Diet safety at a glance

Volumetrics Diet overall Generally safe As a balanced whole-food eating pattern, it is generally safe for most healthy adults.
Pregnancy Use caution Pregnancy is not a time for active weight loss; talk with your doctor before changing your diet.
Breastfeeding Use caution Nursing parents have higher calorie and nutrient needs, so check with your doctor before restricting intake.

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

Still wondering about combining Macitentan and Volumetrics Diet? 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 Volumetrics Diet. 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 follow Volumetrics Diet and take the medicine. 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. Volumetrics Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Volumetrics Diet side to compare — that is a limit of the record, not a statement that Volumetrics Diet has no side effects.

Everything else you take

See Every Supplement That Interacts With Macitentan

This page covers Volumetrics Diet 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 Volumetrics Diet 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 Volumetrics Diet
Steady interest

#1,266 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Macitentan
Top 25%

#507 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. Volumetrics Diet 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 Volumetrics Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Volumetrics Diet 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 .
Eating pattern

About Volumetrics Diet

What is Volumetrics Diet?

  • Weight loss
  • Weight management
  • Feeling fuller on fewer calories
  • Healthier eating habits
  • Reducing overeating

The Volumetrics Diet is an eating plan, not an herb or supplement. It focuses on choosing foods that are low in calories but high in volume—like vegetables, fruits, broth-based soups, and lean proteins—so you feel full while eating fewer calories. It is generally considered a balanced, safe approach to weight management, but results depend on consistency, and you should talk with a doctor or dietitian before starting any weight-loss plan.

Eating plan / dietary pattern (not a pill or supplement)

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

Volumetrics Diet: dosing

There is no pill, capsule, or standardized "dose" for the Volumetrics Diet because it is an eating pattern, not a supplement.Instead of a dose, the plan guides you to build meals around low-energy-density foods, fill about half your plate with vegetables and fruit, and limit high-calorie foods. They can help you follow the approach safely and realistically.

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

Read the full Volumetrics Diet 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 & Volumetrics Diet

Browse every other medication we’ve checked against Volumetrics Diet — 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

Volumetrics Diet References

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

  1. Choosing a Safe and Successful Weight-Loss Program — NIH National Institute of Diabetes and Digestive and Kidney Diseases Source
  2. Healthy Weight, Nutrition, and Physical Activity — Centers for Disease Control and Prevention 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

Following Volumetrics Diet While Taking Macitentan: Common Questions

Is it safe to follow Volumetrics Diet while taking Macitentan?
We do not list a known interaction between Volumetrics Diet 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 — Volumetrics Diet 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 Volumetrics Diet?

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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.