Drug & supplement interaction

Lavender + Cobicistat

Cobicistat brand name: Tybost.

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 Lavender and Cobicistat 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 label for Cobicistat states a food rule worth keeping to, and 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

Lavender and Cobicistat

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 Cobicistat and Lavender 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.

Lavender safety at a glance

Lavender overall Use caution Generally well tolerated in approved forms, but essential oil is toxic if swallowed and skin contact can irritate some people.
Pregnancy Use caution Not enough reliable safety data, so avoid medicinal amounts unless your doctor approves.
Breastfeeding Use caution Safety is not well studied, so use only with guidance from your healthcare provider.

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

Still wondering about combining Cobicistat and Lavender? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Cobicistat

Interactions in our licensed database are recorded against drug classes, not just single drug names. Cobicistat is filed under 2 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, oral drugs. Lavender has documented interactions with 1 drug class — the most serious being cns depressants (moderate) — and none of Cobicistat’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

Lavender Does Interact With Other Medications

Lavender has 248 moderate known drug interactions in our database — Cobicistat isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Cobicistat)
Taking anything else?

Check Another of Your Medications Against Lavender

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

What to actually watch for

No Interaction Found — But Data Suggests Lavender and Cobicistat 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. One of them is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on reported in 44.9% of FDA reports for Cobicistat Additional detail

    Lavender

    “In one case report, a 24-year-old male presented with shortness of breath, weakness, nausea, and decreased urine output following the intake of Spanish lavender tea twice daily for 5 days. After presenting to the hospital, the patient was diagnosed with acute kidney failure secondary to acute interstitial nephritis likely due to lavender consumption.”

    Lavender · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 112259. Ozer H, Sayan ZA, Baloglu I, Ozturk Y, Yonet F, Turkmen K. Unknown criminals for kidney: Acute interstitial nephritis due to lavender tea. Explore (NY) 2023. PubMed

    Cobicistat

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

  • Itching Additional detail

    Lavender

    “Topically, use of lavender oil, such as in personal care products, might cause allergic contact dermatitis in some patients (6,101728). There have been numerous case reports of allergic contact dermatitis and eczema linked to lavender oil exposure from shampoos, lotions, fragrances, or direct application of oil to pillows.”

    Lavender · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 101728. Bingham LJ, Tam MM, Palmer AM, Cahill JL, Nixon RL. Contact allergy and allergic contact dermatitis caused by lavender: A retrospective study from an Australian clinic. Contact Dermatitis. 2019;81(1):37-42. PubMed
    3. 10031. Varma S, Blackford S, Statham BN, Blackwell A. Combined contact allergy to tea tree oil and lavender oil complicating chronic vulvovaginitis. Contact Dermatitis 2000;42:309-10.
    4. 58043. Coulson IH and Khan AS. Facial 'pillow' dermatitis due to lavender oil allergy. Contact Dermatitis 1999;41(2):111. PubMed
    5. 58109. Brandao FM. Occupational allergy to lavender oil. Contact Dermatitis 1986;15(4):249-250. PubMed
    6. 58120. Rademaker M. Allergic contact dermatitis from lavender fragrance in Difflam gel. Contact Dermatitis 1994;31(1):58-59. PubMed

    Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Cobicistat. Read the label on DailyMed ›

  • Diarrhea / Nausea Additional detail

    Lavender

    “Orally, lavender oil, including a specific lavender oil ingredient (Silexan, Dr Willmar Schwabe GmbH & Co. KG), may cause gastrointestinal disturbance, including dyspepsia, diarrhea, breath odor, eructation, and nausea. Tincture of lavender has been linked to cases of constipation and increased appetite; however, it is unknown if this occurred at a greater rate than with placebo.”

    Lavender · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 58077. Woelk, H. and Schlafke, S. A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine. 2010;17(2):94-99. PubMed
    2. 58080. Kasper, S., Gastpar, M., Muller, W. E., Volz, H. P., Moller, H. J., Dienel, A., and Schlafke, S. Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, plac
    3. 58098. Uehleke, B., Schaper, S., Dienel, A., Schlaefke, S., and Stange, R. Phase II trial on the effects of Silexan in patients with neurasthenia, post-traumatic stress disorder or somatization disorder. Phytomedicine. 6-15-2012;19(8-9):665-671. PubMed
    4. 93004. Kasper S, Gastpar M, Müller WE, et al. Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine. Int J Neuropsychopharmacol. 2014 Jun;17(6):859-69. PubMed
    5. 103061. Donelli D, Antonelli M, Bellinazzi C, Gensini GF, Firenzuoli F. Effects of lavender on anxiety: A systematic review and meta-analysis. Phytomedicine. 2019;65:153099. PubMed
    6. 114631. Kasper S, Volz HP, Möller HJ, et al. Lavender oil preparation Silexan is effective in mild-to-moderate major depression: a randomized, placebo- and reference-controlled trial. Eur Arch Psychiatry Clin Neurosci 2024. PubMed

    Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Cobicistat. Read the label on DailyMed ›

  • A skin rash Additional detail

    Lavender

    Recorded for Lavender in the same Natural Medicines adverse-effect record shown under Diarrhea / Nausea above.

    Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Cobicistat. Read the label on DailyMed ›

  • Headache Additional detail

    Lavender

    “Orally, lavender flower powder, tincture of lavender containing 50% alcohol, and a specific lavender oil ingredient (Silexan) have been linked to headache. Headache has also been reported rarely following lavender oil aromatherapy.”

    Lavender · Natural Medicines adverse-effect record, reported in cluster headache.

    3 sources cited
    1. 9792. Akhondzadeh S, Kashani L, Fotouhi A, et al. Comparison of Lavandula angustifolia Mill. tincture and imipramine in the treatment of mild to moderate depression: a double-blind, randomized trial. Prog Neuropsychopharmacol Biol Psychiatry 2003;27:123-7. PubMed
    2. 103061. Donelli D, Antonelli M, Bellinazzi C, Gensini GF, Firenzuoli F. Effects of lavender on anxiety: A systematic review and meta-analysis. Phytomedicine. 2019;65:153099. PubMed
    3. 109860. Firoozeei TS, Feizi A, Rezaeizadeh H, Zargaran A, Roohafza HR, Karimi M. The antidepressant effects of lavender (Lavandula angustifolia Mill.): A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Med 2021;59:102 PubMed

    Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Cobicistat. Read the label on DailyMed ›

Reported for Lavender but not commonly for Cobicistat: stomach upset, shortness of breath, increased appetite and constipation.

Effects for Cobicistat come from the ADVERSE REACTIONS section of its FDA label; effects for Lavender come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 20,779 voluntary FDA FAERS reports for Cobicistat 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.

How to take them

Some Cobicistat Products Have a Food Rule — Lavender Should Not Break It

At least one FDA label for a product containing Cobicistat says to take it with food. If you take Lavender on an empty stomach out of habit, keep them separate — and take Cobicistat with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Cobicistat products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION TYBOST must be coadministered with atazanavir or darunavir at the same time, with food, and in combination with other HIV-1 antiretroviral agents.

From the Dosage and Administration section of the FDA label we read for Cobicistat — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Lavender or Cobicistat

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

This page covers Lavender only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cobicistat page lists 30 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), Cannabidiol (cbd) (moderate), Cannabinol (cbn) (moderate) and Cannabis (moderate).

By severity: 1 major · 19 moderate · 10 minor.

From our pharmacist’s overview on the Cobicistat page

“Activated charcoal is the one entry to understand first if you take cobicistat (Tybost). Charcoal soaks up drugs in the gut, and since cobicistat's entire job is boosting an HIV medicine to protective levels, blunting its absorption can put the whole regimen at risk.”

Reviewed by 2 · Jul 18, 2026

Open the Cobicistat interaction page

One more smart check

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

We hold 75 real supplement products containing Lavender, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lavender. Even though Lavender itself has no known interaction with Cobicistat, 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 Lavender and Cobicistat 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 Lavender
Top 25%

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

29 days ago today
Medication Cobicistat
Steady interest

#2,648 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 Lavender reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Lavender and Cobicistat 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 Lavender

What is Lavender?

Lavender
  • Anxiety and stress
  • Sleep problems
  • Relaxation and calming
  • Minor skin conditions
  • Aromatherapy

Lavender is a fragrant herb most popular for promoting relaxation, easing anxiety, and supporting sleep, with some encouraging evidence for a standardized oral lavender oil product for anxiety. While generally well tolerated, the essential oil should never be swallowed unless made for that purpose, and pregnant or breastfeeding people should use caution and talk to a healthcare provider first.

Lavandula angustifolia · Lamiaceae · Flowers and essential oil · Essential oil, oral capsules, tea, dried flowers, aromatherapy products, topical creams

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

Lavender: dosing

There is no single standardized dose of lavender that fits all products or all uses. The right amount depends on the form, whether it is a tea, capsule, oil, or aromatherapy product.The best approach is to follow the directions on the product label and not exceed the recommended amount. Essential oil intended for aromatherapy or diluted skin use should not be swallowed.

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

Read the full Lavender monograph & all interactions
Medication

About Cobicistat

What Is Cobicistat Used For?

Brand name: Tybost

Tybost (cobicistat) is not itself an HIV treatment — it works by slowing the breakdown of certain HIV medicines so they stay active in your body long enough to work. Specifically, Tybost is used to boost the HIV medicines atazanavir or darunavir (once-daily dosing) as part of a complete HIV-1 treatment regimen in adults and in children weighing at least 14 kg (about 31 lbs).

Tybost is not interchangeable with ritonavir (another booster) for all HIV medicines. It is not recommended with darunavir twice-daily, fosamprenavir, saquinavir, or tipranavir.

Most-Reported Side Effects for Cobicistat

From FAERS, the FDA’s public side-effect reporting system (20,779 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Bone density decreased 8,112 reports
Chronic kidney disease 4,754 reports
Renal injury 4,577 reports
Tooth loss 4,186 reports
Bone loss 4,107 reports
See full Cobicistat drug information
Keep checking

Other Drugs & Lavender

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

0Major
248Moderate
0Minor
2,581No known interaction
248 Moderate 2,581 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Lavender page.

No interaction 2,581 drugs checked — show the list

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

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full Lavender list.

See the full Lavender interactions page
See every supplement checked against Cobicistat, ranked by severity
Evidence & sources

Lavender References

The 20 references that drive our Lavender 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. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
  3. Akhondzadeh S, Kashani L, Fotouhi A, et al. Comparison of Lavandula angustifolia Mill. tincture and imipramine in the treatment of mild to moderate depression: a double-blind, randomized trial. Prog Neuropsychopharmacol Biol Psychiatry 2003;27:123-7. PubMed
  4. Varma S, Blackford S, Statham BN, Blackwell A. Combined contact allergy to tea tree oil and lavender oil complicating chronic vulvovaginitis. Contact Dermatitis 2000;42:309-10.
  5. Coulson IH and Khan AS. Facial 'pillow' dermatitis due to lavender oil allergy. Contact Dermatitis 1999;41(2):111. PubMed
  6. Woelk, H. and Schlafke, S. A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine. 2010;17(2):94-99. PubMed
  7. Kasper, S., Gastpar, M., Muller, W. E., Volz, H. P., Moller, H. J., Dienel, A., and Schlafke, S. Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, plac
  8. Uehleke, B., Schaper, S., Dienel, A., Schlaefke, S., and Stange, R. Phase II trial on the effects of Silexan in patients with neurasthenia, post-traumatic stress disorder or somatization disorder. Phytomedicine. 6-15-2012;19(8-9):665-671. PubMed
  9. Brandao FM. Occupational allergy to lavender oil. Contact Dermatitis 1986;15(4):249-250. PubMed
  10. Rademaker M. Allergic contact dermatitis from lavender fragrance in Difflam gel. Contact Dermatitis 1994;31(1):58-59. PubMed
  11. Kasper S, Gastpar M, Müller WE, et al. Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine. Int J Neuropsychopharmacol. 2014 Jun;17(6):859-69. PubMed
  12. Farshbaf-Khalili A, Kamalifard M, Namadian M. Comparison of the effect of lavender and bitter orange on anxiety in postmenopausal women: A triple-blind, randomized, controlled clinical trial. Complement Ther Clin Pract 2018;31:132-8. PubMed
  13. Bingham LJ, Tam MM, Palmer AM, Cahill JL, Nixon RL. Contact allergy and allergic contact dermatitis caused by lavender: A retrospective study from an Australian clinic. Contact Dermatitis. 2019;81(1):37-42. PubMed
  14. Donelli D, Antonelli M, Bellinazzi C, Gensini GF, Firenzuoli F. Effects of lavender on anxiety: A systematic review and meta-analysis. Phytomedicine. 2019;65:153099. PubMed
  15. Firoozeei TS, Feizi A, Rezaeizadeh H, Zargaran A, Roohafza HR, Karimi M. The antidepressant effects of lavender (Lavandula angustifolia Mill.): A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Med 2021;59:102 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 Lavender and Cobicistat Together: Common Questions

Is it safe to take Lavender with Cobicistat?
We do not list a known interaction between Lavender and Cobicistat. 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 Lavender and Cobicistat have any of the same side effects?
Yes — our sources link each of them separately to 6 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.
Should I take Lavender and Cobicistat at the same time of day?
At least one FDA label for a product containing Cobicistat says to take it with food. If you take Lavender on an empty stomach out of habit, keep them separate and take Cobicistat with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Cobicistat products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Lavender and Cobicistat combination checked?
Interactions in our licensed database are recorded against drug classes. Cobicistat is filed under 2 classifications, and Lavender has documented interactions with 1 drug class — none of Cobicistat'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 Lavender interact with any other medications?
Yes. Lavender has 248 documented drug interactions in our database — Cobicistat 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 Cobicistat interact with any supplements?
Yes. Cobicistat has documented interactions with 30 supplements in our database — Lavender is not one of them. The Cobicistat 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

Lavender monograph Uses, safety profile, and every drug interaction in one place Cobicistat drug information The full plain-English guide to this medication Cobicistat supplement interactions Every supplement checked against Cobicistat, 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 20 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Cobicistat and Lavender?

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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.