Drug & supplement interaction

Henna + Levothyroxine

Levothyroxine brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, and others.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Henna and Levothyroxine 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 Levothyroxine 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

Henna and Levothyroxine

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 Levothyroxine and Henna 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.

Henna safety at a glance

Henna overall Use caution Natural henna is generally safe applied to skin and hair, but 'black henna' and oral use can be harmful.
Pregnancy Unsafe When used orally. Henna is believed to have abortifacient properties. There is insufficient reliable information available about the safety of henna when used t... Read the full pregnancy detail
Breastfeeding Unsafe When used orally. Henna is believed to have abortifacient properties. There is insufficient reliable information available about the safety of henna when used t... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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

Why No Interaction Is Listed for Levothyroxine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levothyroxine is filed under 3 classifications — including thyroid hormone, oral drugs. Henna has documented interactions with 1 drug class — the most serious being lithium (moderate) — and none of Levothyroxine’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

Henna Does Interact With Other Medications

Henna has 1 moderate known drug interaction in our database — Levothyroxine isn’t one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Henna

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

What to actually watch for

No Interaction Found — But Data Suggests Henna and Levothyroxine 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. 4 of them are worth acting on rather than waiting out — marked below.

  • Wheezing / Hives Worth acting on Additional detail

    Henna

    “Topically, henna can cause allergic contact dermatitis, with symptoms of redness, itching, burning, swelling, scaling, fissuring, papules, blisters, and scarring. Although some allergic reactions to pure henna have been confirmed with skin patch testing, most reported allergic reactions to henna are due to the added compound para-phenylenediamine (PPD). PPD is not found naturally in henna.”

    Henna · Natural Medicines adverse-effect record, reported in asthma.

    6 sources cited
    1. 1370. Lyon MJ, Shaw JC. Allergic contact dermatitis reaction to henna. Arch Dermatol 2000;136:124-5. PubMed
    2. 4146. Garcia Ortiz JC, Terron M, Bellido J. Contact allergy to henna. Int Arch Allergy Immunol 1997;114:298-9. PubMed
    3. 6144. Lewin PK. Temporary henna tattoo with permanent scarification. CMAJ 1999;160:310.
    4. 6145. Lestringant GG, Bener A, Frossard PM. Cutaneous reactions to henna and associated additives. Br J Dermatol 1999;141:598-600. PubMed
    5. 6146. Etienne A, Piletta P, Hauser C, Pasche-Koo F. Ectopic contact dermatitis from henna. Contact Dermatitis 1997;:183. PubMed
    6. 6147. Wantke F, Gotz M, Jarisch R. Contact dermatitis due to henna, solvent red 1 and solvent red 3, a case report. Contact Dermatitis 1992;27:346-7. PubMed

    Levothyroxine

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

  • Shortness of breath Worth acting on Additional detail

    Henna

    “Topically, henna has been associated with hemolysis, anemia, reticulocytosis, and indirect hyperbilirubinemia in infants and children with glucose 6-phosphate dehydrogenase (G6PD) deficiency.

    Orally, henna might also have this effect in adults, particularly in those with G6PD deficiency.”

    Henna · Natural Medicines adverse-effect record, reported in anemia.

    6 sources cited
    1. 4147. Kandil HH, al-Ghanem MM, Sarwat MA, al-Thallab FS. Henna (Lawsonia inermis Linn.) inducing haemolysis among G6PD-deficient newborns. A new clinical observation. Ann Trop Paediatr 1996;16:287-91. PubMed
    2. 10381. Raupp P, Hassan JA, Varughese M, Kristiansson B. Henna causes life threatening haemolysis in glucose-6-phosphate dehydrogenase deficiency. Arch Dis Child 2001;85:411-2.. PubMed
    3. 100839. Katar S, Devecioglu C, Ozbek MN, Ecer S. Henna causes life-threatening hyperbilirubinaemia in glucose-6-phosphate dehydrogenase deficiency. Clin Exp Dermatol. 2007;32(2):235-6. PubMed
    4. 100840. Kheir A, Gaber I, Gafer S, Ahmed W. Life-threatening haemolysis induced by henna in a Sudanese child with glucose-6-phosphate dehydrogenase deficiency. East Mediterr Health J. 2017;23(1):28-30.
    5. 100852. Rund D, Schaap T, Da'as N, Ben Yehuda D, Kalish J. Plasma exchange as treatment for Lawsone (henna) intoxication. J Clin Apher. 2007;22(4):243-5. PubMed
    6. 104797. Asgari S, Esfandbod M, Haghshomar M. Henna-induced hemolysis and acute kidney injury in an 85-year-old man; A case report. Arch Acad Emerg Med. 2020 Oct 14;8(1):e82.

    Levothyroxine

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

  • An allergic reaction Worth acting on Additional detail

    Henna

    “Orally, henna can cause an upset stomach, possibly due to tannin content (18,104797). Henna has also been linked to rhabdomyolysis, renal injury and failure, hemolytic anemia, and mortality when taken orally.

    Topically, henna can cause contact dermatitis, including redness, itching, burning, swelling, scaling, fissuring, papules, blisters, and scarring.”

    Henna · Natural Medicines adverse-effect record, reported in anemia.

    6 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 104797. Asgari S, Esfandbod M, Haghshomar M. Henna-induced hemolysis and acute kidney injury in an 85-year-old man; A case report. Arch Acad Emerg Med. 2020 Oct 14;8(1):e82.
    3. 100852. Rund D, Schaap T, Da'as N, Ben Yehuda D, Kalish J. Plasma exchange as treatment for Lawsone (henna) intoxication. J Clin Apher. 2007;22(4):243-5. PubMed
    4. 1370. Lyon MJ, Shaw JC. Allergic contact dermatitis reaction to henna. Arch Dermatol 2000;136:124-5. PubMed
    5. 4146. Garcia Ortiz JC, Terron M, Bellido J. Contact allergy to henna. Int Arch Allergy Immunol 1997;114:298-9. PubMed
    6. 6144. Lewin PK. Temporary henna tattoo with permanent scarification. CMAJ 1999;160:310.

    Levothyroxine

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

  • Fever / Diarrhea Additional detail

    Henna

    “Orally, henna can cause an upset stomach, possibly due to tannin content (18,104797). Ingestion of henna might also exacerbate diseases such as ulcerative colitis, although evidence is limited. A 45-year-old female with ulcerative colitis in remission reportedly experienced 10 days of chemical colitis with symptoms of severe bloody diarrhea, abdominal pain, and fever, starting one week after ingesting one liter of di…”

    Henna · Natural Medicines adverse-effect record, reported in diarrhea.

    3 sources cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
    2. 104797. Asgari S, Esfandbod M, Haghshomar M. Henna-induced hemolysis and acute kidney injury in an 85-year-old man; A case report. Arch Acad Emerg Med. 2020 Oct 14;8(1):e82.
    3. 100854. Uygur-Bayramicli O, Dabak R, Sargin M. Acute chemical colitis resulting from oral intake of henna. J Clin Gastroenterol. 2005;39(10):920-1. PubMed

    Levothyroxine

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

  • Itching / A skin rash Additional detail

    Henna

    Recorded for Henna in the same Natural Medicines adverse-effect record shown under An allergic reaction above.

    Levothyroxine

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

  • Stomach pain Additional detail

    Henna

    Recorded for Henna in the same Natural Medicines adverse-effect record shown under Shortness of breath above.

    Levothyroxine

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

Reported for Henna but not commonly for Levothyroxine: kidney problems, severe muscle breakdown, stomach upset and swelling.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Henna come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Henna in Pregnancy & Breastfeeding

Pregnancy And Lactation Unsafe

When used orally. Henna is believed to have abortifacient properties. There is insufficient reliable information available about the safety of henna when used topically; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Levothyroxine Products Have a Food Rule — Henna Should Not Break It

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Henna included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Levothyroxine on its own and move Henna to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Levothyroxine 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.

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 Henna or Levothyroxine

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

This page covers Henna only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levothyroxine page lists 50 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 39 moderate · 9 minor.

From our pharmacist’s overview on the Levothyroxine page

“Levothyroxine replaces a hormone your body measures in tiny amounts, so small shifts in its blood level show up in how you feel, and I treat this list with genuine care. Nearly everything on it does one of two things: blocks the pill from being absorbed in the gut, the way everyday minerals like calcium do by binding it into complexes,…”

Reviewed by 2 · Jul 18, 2026

Open the Levothyroxine interaction page

One more smart check

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

We hold 9 real supplement products containing Henna, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Henna. Even though Henna itself has no known interaction with Levothyroxine, 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 Henna and Levothyroxine 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 Henna
Steady interest

#1,389 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Levothyroxine
Top 10

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

What is Henna?

  • Hair and skin dye
  • Cooling and skin care
  • Wound and skin healing (traditional)
  • Antimicrobial and antifungal (traditional)
  • Nail and scalp conditions

Henna is a plant most widely used as a natural dye for hair, skin, and nails, and has a long history in traditional medicine for skin and minor wound care. Strong human evidence for medicinal benefits is limited, and pure (natural) henna applied to skin is generally well tolerated, but so-called 'black henna' products can cause serious skin reactions. Talk to a pharmacist or doctor before using henna for any health purpose, and avoid taking it by mouth.

Lawsonia inermis · Lythraceae · Leaves (also bark, seeds, and flowers in traditional use) · Dried leaf powder, paste, oil, and occasionally extracts; mostly used topically for hair and skin

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

Henna: dosing

There is no established medicinal dose for henna. It is mainly used externally as a paste or powder for dyeing hair, skin, and nails, and the amount used depends on the cosmetic purpose.If you choose to use a henna product, follow the directions on the label and choose pure, natural henna from a reputable source. Avoid products labeled or sold as 'black henna' because of the risk of serious reactions.Henna should not be taken by mouth.

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

Read the full Henna monograph & all interactions
Medication

About Levothyroxine

What Is Levothyroxine Used For?

Brand names: Euthyrox, Levothroid, Unithroid, Synthroid, Levoxyl, Levo-T, Eltroxin, Estre, Levothyroxine, Novothyrox, Levolet

Levothyroxine replaces or supplements the thyroid hormone your body isn't making enough of. It's used for hypothyroidism — an underactive thyroid — in adults, children, and even newborns, whether the cause is the thyroid gland itself, the pituitary gland, or the hypothalamus in the brain.

It's also used alongside surgery and radioiodine treatment in people with certain types of thyroid cancer, to help suppress the hormone that can stimulate cancer growth. It is not meant for weight loss, treating benign thyroid nodules in people who have enough iodine, or for hypothyroidism during recovery from a temporary condition called subacute thyroiditis.

See full Levothyroxine drug information
Keep checking

Other Drugs & Henna

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

0Major
1Moderate
0Minor
2,828No known interaction
Moderate

1 interaction

No interaction 2,828 drugs checked — show the list
Evidence & sources

Henna References

The 30 references that drive our Henna 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  3. Lyon MJ, Shaw JC. Allergic contact dermatitis reaction to henna. Arch Dermatol 2000;136:124-5. PubMed
  4. Garcia Ortiz JC, Terron M, Bellido J. Contact allergy to henna. Int Arch Allergy Immunol 1997;114:298-9. PubMed
  5. Kandil HH, al-Ghanem MM, Sarwat MA, al-Thallab FS. Henna (Lawsonia inermis Linn.) inducing haemolysis among G6PD-deficient newborns. A new clinical observation. Ann Trop Paediatr 1996;16:287-91. PubMed
  6. Majoie IM, Bruynzeel DP. Occupational immediate-type hypersensitivity to henna in a hairdresser. Am J Contact Dermat 1996;7:38-40. DOI
  7. Lewin PK. Temporary henna tattoo with permanent scarification. CMAJ 1999;160:310.
  8. Lestringant GG, Bener A, Frossard PM. Cutaneous reactions to henna and associated additives. Br J Dermatol 1999;141:598-600. PubMed
  9. Etienne A, Piletta P, Hauser C, Pasche-Koo F. Ectopic contact dermatitis from henna. Contact Dermatitis 1997;:183. PubMed
  10. Wantke F, Gotz M, Jarisch R. Contact dermatitis due to henna, solvent red 1 and solvent red 3, a case report. Contact Dermatitis 1992;27:346-7. PubMed
  11. Nigam PK, Saxena AK. Allergic contact dermatitis from henna. Contact Dermatitis 1988;18:55-6. PubMed
  12. Gupta BN, Mathur AK, Agarwal C, Singh A. Contact sensitivity to henna. Contact Dermatitis 1986;15:303-4. PubMed
  13. Pasricha JS, Gupta R, Panjwani S. Contact dermatitis to henna (Lawsonia). Contact Dermatitis 1980;6:288-9. PubMed
  14. Cronin E. Immediate type hypersensitivity to henna. Contact Dermatitis 1979;5:198-9. PubMed
  15. Raupp P, Hassan JA, Varughese M, Kristiansson B. Henna causes life threatening haemolysis in glucose-6-phosphate dehydrogenase deficiency. Arch Dis Child 2001;85:411-2.. 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 Henna and Levothyroxine Together: Common Questions

Is it safe to take Henna with Levothyroxine?
We do not list a known interaction between Henna and Levothyroxine. 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 Henna and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to 9 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 Henna and Levothyroxine at the same time of day?
At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Levothyroxine on its own and move Henna to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Henna and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Henna has documented interactions with 1 drug class — none of Levothyroxine'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 Henna interact with any other medications?
Yes. Henna has 1 documented drug interaction in our database — Levothyroxine 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 Levothyroxine interact with any supplements?
Yes. Levothyroxine has documented interactions with 50 supplements in our database — Henna is not one of them. The Levothyroxine 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 Levothyroxine and Henna?

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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.