Drug & supplement interaction

Lorenzo's Oil + Efavirenz

Efavirenz brand name: Sustiva.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Lorenzo's Oil and Efavirenz 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

Lorenzo's Oil and Efavirenz

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 Efavirenz and Lorenzo's Oil 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 Lorenzo's Oil at all — not against Efavirenz, 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.

Lorenzo's Oil safety at a glance

Lorenzo's Oil overall Use caution It is a medical treatment for a rare disease and should only be used under specialist supervision, not as a general supplement.
Pregnancy Avoid Safety in pregnancy is not established; use only if a specialist directs it.
Breastfeeding Avoid Safety while breastfeeding is not established; talk to your doctor first.

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

Still wondering about combining Efavirenz and Lorenzo's Oil? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Lorenzo's Oil Itself Has Been Linked To

This is not an interaction — nothing below involves Efavirenz. It is the side-effect record for Lorenzo's Oil on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Lorenzo's Oil, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • A low platelet count / A low white blood cell count / Bleeding or bruising Worth acting on Additional detail

    “Orally, Lorenzo's oil can cause thrombocytopenia, neutropenia, purpura, petechiae, and bleeding (6,924,926,927).”

    Lorenzo's Oil · Natural Medicines adverse-effect record, reported in thrombocytopenia.

    4 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 924. Aubourg P, Adamsbaum C, Lavallard-Rousseau MC, et al. A two-year trial of oleic and erucic acids (Lorenzo's oil) as treatment for adrenomyeloneuropathy. N Engl J Med 1993;329:745-52. PubMed
    3. 926. Chai BC, Etches WS, Stewart MW, Siminoski K. Bleeding in a patient taking Lorenzo's oil: evidence for a vascular defect. Postgrad Med J 1996;72:113-4.
    4. 927. Revell P, Green A, Green S. Platelets in treated adrenoleukodystrophy: a brief report. J Inherit Metab Dis 1995;18:635-7. PubMed

    “Orally, Lorenzo's oil can cause thrombocytopenia, purpura, petechiae, bleeding, and neutropenia (6,924,926,927).”

    Lorenzo's Oil · Natural Medicines adverse-effect record, reported in thrombocytopenia.

    4 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 924. Aubourg P, Adamsbaum C, Lavallard-Rousseau MC, et al. A two-year trial of oleic and erucic acids (Lorenzo's oil) as treatment for adrenomyeloneuropathy. N Engl J Med 1993;329:745-52. PubMed
    3. 926. Chai BC, Etches WS, Stewart MW, Siminoski K. Bleeding in a patient taking Lorenzo's oil: evidence for a vascular defect. Postgrad Med J 1996;72:113-4.
    4. 927. Revell P, Green A, Green S. Platelets in treated adrenoleukodystrophy: a brief report. J Inherit Metab Dis 1995;18:635-7. PubMed
  • A higher chance of infection Worth acting on Additional detail

    “In one case report, a 39-year-old man with adrenoleukodystrophy developed lipoid pneumonia while taking Lorenzo's oil. He presented with respiratory failure; bronchoalveolar lavage produced fluid with an oily appearance.”

    Lorenzo's Oil · Natural Medicines adverse-effect record, reported in adrenoleukodystrophy (ald).

    1 source cited
    1. 99422. Majori M, Scarascia A, Anghinolfi M, et al. Lipoid pneumonia as a complication of Lorenzo's oil therapy in a patient with adrenoleukodystrophy. J Bronchology Interv Pulmonol 2014;21(3):271-3. doi: 10.1097/LBR.0000000000000084. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Lorenzo's Oil — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Efavirenz’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Efavirenz column appears here.

Everything else you take

See Every Supplement That Interacts With Efavirenz

This page covers Lorenzo's Oil only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Efavirenz page lists 159 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 117 moderate · 39 minor.

From our pharmacist’s overview on the Efavirenz page

“Efavirenz (Sustiva) is an HIV medicine, so an interaction that weakens it can cost more than a bad day; it can invite viral resistance. That makes this a list to treat with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Efavirenz interaction page

How much people look this up

Where Lorenzo's Oil and Efavirenz 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 Lorenzo's Oil
Steady interest

#1,367 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Efavirenz
Top half

#909 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 Lorenzo's Oil reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Lorenzo's Oil and Efavirenz 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 Lorenzo's Oil

What is Lorenzo's Oil?

  • Adrenoleukodystrophy (ALD)
  • Adrenomyeloneuropathy (AMN)
  • Lowering very long-chain fatty acids in blood
  • Slowing progression of certain inherited disorders

Lorenzo's Oil is not a typical herbal supplement—it is a specially formulated mixture of two fatty acids (glyceryl trioleate and glyceryl trierucate, in a 4:1 ratio) developed to lower very long-chain fatty acids in people with adrenoleukodystrophy (ALD). It can normalize blood fatty acid levels and may help delay disease in some boys who are not yet showing symptoms, but it is not a cure and should only be used under specialist medical supervision.

Refined plant-derived oils (rapeseed/olive oil sources) · Oral liquid oil (prescription-style medical formulation)

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

Lorenzo's Oil: dosing

There is no standard over-the-counter dose for Lorenzo's Oil. When used medically, the amount is calculated by a specialist based on the person's body and is adjusted using blood tests and a carefully controlled low-fat diet.Because dosing must be individualized and monitored, you should not try to dose this product yourself. Do not use it as a casual supplement.

From our Lorenzo's Oil monograph — the full record covers uses, side effects and every documented interaction.

Read the full Lorenzo's Oil monograph & all interactions
Medication

About Efavirenz

What Is Efavirenz Used For?

Brand name: Sustiva

Efavirenz is used to treat HIV-1 (human immunodeficiency virus type 1) infection. It is always used together with other antiretroviral medicines — never on its own.

It is approved for adults and for children who are at least 3 months old and weigh at least 3.5 kg (about 7.7 lbs). Both the capsule and tablet forms are approved for this use.

Most-Reported Side Effects for Efavirenz

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Virologic failure 960 reports
Drug resistance 742 reports
Viral mutation identified 676 reports
Pathogen resistance 641 reports
Foetal exposure during pregnancy 621 reports
See full Efavirenz drug information
Keep checking

Other Drugs & Lorenzo's Oil

Browse every other medication we’ve checked against Lorenzo's Oil — 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
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Lorenzo's Oil list.

See the full Lorenzo's Oil interactions page
See every supplement checked against Efavirenz, ranked by severity
Evidence & sources

Lorenzo's Oil References

The 12 references that drive our Lorenzo's Oil 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Kaplan PW, Tusa RJ, Shankroff J, et al. Visual evoked potentials in adrenoleukodystrophy: a trial with glycerol trioleate and Lorenzo oil. Ann Neurol 1993;34:169-74.
  3. Poulos A, Gibson R, Sharp P, et al. Very long chain fatty acids in X-linked adrenoleukodystrophy brain after treatment with Lorenzo's oil. Ann Neurol 1994;36:741-6. PubMed
  4. Duchesne N, Dufour M, Bouchard G, et al. Adrenoleukodystrophy: magnetic resonance follow-up after Lorenzo's oil therapy. Can Assoc Radiol J 1995;46:386-91.
  5. Moser HW. Clinical and therapeutic aspects of adrenoleukodystrophy and adrenomyeloneuropathy. J Neuropathol Exp Neurol 1995;54:740-5. PubMed
  6. Aubourg P, Adamsbaum C, Lavallard-Rousseau MC, et al. A two-year trial of oleic and erucic acids (Lorenzo's oil) as treatment for adrenomyeloneuropathy. N Engl J Med 1993;329:745-52. PubMed
  7. Chai BC, Etches WS, Stewart MW, Siminoski K. Bleeding in a patient taking Lorenzo's oil: evidence for a vascular defect. Postgrad Med J 1996;72:113-4.
  8. Revell P, Green A, Green S. Platelets in treated adrenoleukodystrophy: a brief report. J Inherit Metab Dis 1995;18:635-7. PubMed
  9. Maeda K, Suzuki Y, Yajima S, et al. Improvement of clinical and MRI findings in a boy with adrenoleukodystrophy by dietary erucic acid therapy. Brain Dev 1992;14:409-12.
  10. Wong V. Adrenoleukodystrophy in a Chinese boy. Brain Dev 1992;14:276-7. PubMed
  11. Moser HW, Raymond GV, Lu SE, et al. Follow-up of 89 asymptomatic patients with adrenoleukodystrophy treated with Lorenzo's Oil. Arch Neurol 2005;62:1073-80. PubMed
  12. Majori M, Scarascia A, Anghinolfi M, et al. Lipoid pneumonia as a complication of Lorenzo's oil therapy in a patient with adrenoleukodystrophy. J Bronchology Interv Pulmonol 2014;21(3):271-3. doi: 10.1097/LBR.0000000000000084. 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 Lorenzo's Oil and Efavirenz Together: Common Questions

Is it safe to take Lorenzo's Oil with Efavirenz?
We do not list a known interaction between Lorenzo's Oil and Efavirenz. 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 Efavirenz interact with any supplements?
Yes. Efavirenz has documented interactions with 159 supplements in our database — Lorenzo's Oil is not one of them. The Efavirenz 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

Lorenzo's Oil monograph Uses, safety profile, and every drug interaction in one place Efavirenz drug information The full plain-English guide to this medication Efavirenz supplement interactions Every supplement checked against Efavirenz, 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 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Efavirenz and Lorenzo's Oil?

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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.