Drug & supplement interaction

Kinetin + Levothyroxine

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

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 Kinetin 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

Kinetin 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 Kinetin 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.

Kinetin safety at a glance

Kinetin overall Use caution Generally used topically in cosmetics; oral supplement use is not well studied and not recommended.
Pregnancy Avoid There is not enough safety information, so it is best to avoid during pregnancy unless your doctor approves.
Breastfeeding Avoid Safety during breastfeeding has not been established, so caution or avoidance is advised.

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

Still wondering about combining Levothyroxine and Kinetin? 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. Kinetin has documented interactions with 1 drug class — the most serious being anticoagulant/antiplatelet drugs (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

Kinetin Does Interact With Other Medications

Kinetin has 122 moderate known drug interactions in our database — Levothyroxine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 No known interaction 2,708 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Kinetin

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

What to actually watch for

No Interaction Found — But Data Suggests Kinetin 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.

  • Flushing / Itching / A skin rash Additional detail

    Kinetin

    “Orally, the most common adverse effect reported from kinetin is nausea. Headache, diarrhea, tinnitus, flushing, and rash are less common. Topically, kinetin seems to be well tolerated. Erythema, dryness, peeling, burning, stinging, and itching have been reported. However, it is unknown if these symptoms are related to kinetin or other ingredients in the products used.”

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

    3 sources cited
    1. 100046. Gold-von Simson G, Goldberg JD, Rolnitzky LM, et al. Kinetin in familial dysautonomia carriers: implications for a new therapeutic strategy targeting mRNA splicing. Pediatr Res. 2009;65(3):341-6. PubMed
    2. 100044. Wanitphakdeedecha R, Meeprathom W, Manuskiatti W. Efficacy and safety of 0.1% kinetin cream in the treatment of photoaging skin. Indian J Dermatol Venereol Leprol. 2015;81(5):547. PubMed
    3. 100050. Wu JJ, Weinstein GD, Kricorian GJ, Kormeili T, McCullough JL. Topical kinetin 0.1% lotion for improving the signs and symptoms of rosacea. Clin Exp Dermatol. 2007;32(6):693-5. PubMed

    “Orally, kinetin has been reported to cause flushing and rash rarely. Limited research suggests that these reactions are not dose-dependent. Topically, kinetin has been reported to cause erythema, dryness, peeling, burning, stinging, and itching. However, it is unknown if these symptoms are related to kinetin or other ingredients in the products used.”

    Kinetin · Natural Medicines adverse-effect record, reported in erythema.

    2 sources cited
    1. 100046. Gold-von Simson G, Goldberg JD, Rolnitzky LM, et al. Kinetin in familial dysautonomia carriers: implications for a new therapeutic strategy targeting mRNA splicing. Pediatr Res. 2009;65(3):341-6. PubMed
    2. 100044. Wanitphakdeedecha R, Meeprathom W, Manuskiatti W. Efficacy and safety of 0.1% kinetin cream in the treatment of photoaging skin. Indian J Dermatol Venereol Leprol. 2015;81(5):547. PubMed

    Levothyroxine

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

  • Diarrhea / Nausea Additional detail

    Kinetin

    “Orally, the most common adverse effect reported from kinetin is nausea. Lower doses generally cause mild nausea; however, doses of 16.8 mg/kg to 23.5 mg/kg daily increase the chance of severe nausea. Kinetin has also been reported to cause diarrhea, although at a lower rate.”

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

    1 source cited
    1. 100046. Gold-von Simson G, Goldberg JD, Rolnitzky LM, et al. Kinetin in familial dysautonomia carriers: implications for a new therapeutic strategy targeting mRNA splicing. Pediatr Res. 2009;65(3):341-6. PubMed

    Levothyroxine

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

  • Headache Additional detail

    Kinetin

    “Orally, kinetin has been reported to cause headache rarely. Limited research suggests that this reaction is not dose-dependent.”

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

    1 source cited
    1. 100046. Gold-von Simson G, Goldberg JD, Rolnitzky LM, et al. Kinetin in familial dysautonomia carriers: implications for a new therapeutic strategy targeting mRNA splicing. Pediatr Res. 2009;65(3):341-6. PubMed

    Levothyroxine

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

Reported for Kinetin but not commonly for Levothyroxine: ringing in the ears.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Kinetin 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.

How to take them

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

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Kinetin 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 Kinetin 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 Kinetin 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 Kinetin 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 Kinetin 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

How much people look this up

Where Kinetin 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 Kinetin
Steady interest

#1,366 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 Kinetin reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Kinetin 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 Kinetin

What is Kinetin?

  • Anti-aging skincare
  • Skin smoothing and texture
  • Reducing skin dryness and roughness
  • Evening skin tone
  • Cosmetic moisturizing

Kinetin is a plant growth hormone (a cytokinin) used mainly in topical anti-aging and skincare products, not as an oral dietary supplement. Early laboratory research and small studies suggest it may help skin texture and hydration, but high-quality human evidence is limited. If you want to try it, use it as a cosmetic skin product and check with a pharmacist or dermatologist, especially if you have sensitive skin.

Plant-derived cytokinin (a type of plant hormone); used as a purified compound · Topical creams, serums, lotions, and cosmetic skincare products

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

Kinetin: dosing

There is no established standard dose for kinetin, and it is not meant to be taken as an oral supplement. In cosmetic skincare, it appears as one ingredient among many, usually in low concentrations.The best approach is to follow the directions on the product label for how often to apply it. Do not assume that using more product more often will give better results.

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

Read the full Kinetin 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 & Kinetin

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

0Major
122Moderate
0Minor
2,707No known interaction
122 Moderate 2,707 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Kinetin page.

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Kinetin list.

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

Kinetin References

The 7 references that drive our Kinetin 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. Hsiao, G., Shen, M. Y., Lin, K. H., Chou, C. Y., Tzu, N. H., Lin, C. H., Chou, D. S., Chen, T. F., and Sheu, J. R. Inhibitory activity of kinetin on free radical formation of activated platelets in vitro and on thrombus formation in vivo. Eur J Pharmacol PubMed
  2. Adunka, O., Moustaklis, E., Weber, A., May, A., von Ilberg, C., Gstoettner, W., and Kierner, A. C. Labyrinth anesthesia--a forgotten but practical treatment option in Meniere's disease. ORL J Otorhinolaryngol.Relat Spec. 2003;65(2):84-90.
  3. Sheu, J. R., Hsiao, G., Shen, M. Y., Chou, C. Y., Lin, C. H., Chen, T. F., and Chou, D. S. Inhibitory mechanisms of kinetin, a plant growth-promoting hormone, in platelet aggregation. Platelets. 2003;14(3):189-196. PubMed
  4. Wanitphakdeedecha R, Meeprathom W, Manuskiatti W. Efficacy and safety of 0.1% kinetin cream in the treatment of photoaging skin. Indian J Dermatol Venereol Leprol. 2015;81(5):547. PubMed
  5. Gold-von Simson G, Goldberg JD, Rolnitzky LM, et al. Kinetin in familial dysautonomia carriers: implications for a new therapeutic strategy targeting mRNA splicing. Pediatr Res. 2009;65(3):341-6. PubMed
  6. Chiu PC, Chan CC, Lin HM, Chiu HC. The clinical anti-aging effects of topical kinetin and niacinamide in Asians: a randomized, double-blind, placebo-controlled, split-face comparative trial. J Cosmet Dermatol. 2007;6(4):243-9. PubMed
  7. Wu JJ, Weinstein GD, Kricorian GJ, Kormeili T, McCullough JL. Topical kinetin 0.1% lotion for improving the signs and symptoms of rosacea. Clin Exp Dermatol. 2007;32(6):693-5. 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 Kinetin and Levothyroxine Together: Common Questions

Is it safe to take Kinetin with Levothyroxine?
We do not list a known interaction between Kinetin 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 Kinetin and Levothyroxine 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 Kinetin 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 Kinetin 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 Kinetin and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Kinetin 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 Kinetin interact with any other medications?
Yes. Kinetin has 122 documented drug interactions 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 — Kinetin 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

Where next

Keep Exploring

Kinetin monograph Uses, safety profile, and every drug interaction in one place Levothyroxine drug information The full plain-English guide to this medication Levothyroxine supplement interactions Every supplement checked against Levothyroxine, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Kinetin?

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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.