Drug & supplement interaction

Policosanol + 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 Policosanol 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

Policosanol 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 Policosanol 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.

Policosanol safety at a glance

Policosanol overall Use caution Generally well tolerated in studies, but its real-world benefit is uncertain and quality varies between products.
Pregnancy Avoid There is not enough safety information, so it is best to avoid use during pregnancy.
Breastfeeding Avoid There is not enough safety information, so it is best to avoid use while breastfeeding.

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

Still wondering about combining Levothyroxine and Policosanol? 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. Policosanol has documented interactions with 6 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), antidiabetes drugs (moderate) and beta-blockers (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

Policosanol Does Interact With Other Medications

Policosanol has 242 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 242 No known interaction 2,588 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Policosanol

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

What to actually watch for

No Interaction Found — But Data Suggests Policosanol 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.

  • Weight loss Additional detail

    Policosanol

    “Orally, policosanol has been associated with weight loss. However, evidence from a post-market surveillance study of patients taking policosanol 5-15 mg daily shows that this adverse event is uncommon.”

    Policosanol · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    1 source cited
    1. 95375. Fernandez L, Mas R, Illnait J, Fernandez JC. Policosanol: results of a postmarketing surveillance study of 27,879 patients. Curr Ther Res 1998;59(10):717-22. DOI

    Levothyroxine

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

  • Mood changes or irritability Additional detail

    Policosanol

    “Orally, policosanol may cause headache, mild vertigo, somnolence, irritability, or insomnia but these events are uncommon. In one clinical study, 1 out of 44 subjects receiving policosanol 20 mg daily 12 weeks experienced mild vertigo and 2 out of 44 experienced mild headache. In another study, 2 out of 70 patients taking policosanol 10 mg daily for 8 weeks experienced headache.”

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

    3 sources cited
    1. 14404. Greyling A, De Witt C, Oosthuizen W, Jerling JC. Effects of a policosanol supplement on serum lipid concentrations in hypercholesterolaemic and heterozygous familial hypercholesterolaemic subjects. Br J Nutr 2006;95:968-75. PubMed
    2. 69119. Francini-Pesenti F, Brocadello F, Beltramolli D, et al. Sugar cane policosanol failed to lower plasma cholesterol in primitive, diet-resistant hypercholesterolaemia: A double blind, controlled study. Complement Ther Med 2008;16:61-65. PubMed
    3. 95374. Castaño G, Fernández L, Mas R, Illnait J, Mesa M, Fernández JC. Comparison of the effects of policosanol and atorvastatin on lipid profile and platelet aggregation in patients with dyslipidaemia and type 2 diabetes mellitus. Clin Drug Investig. 2003;23(10 PubMed

    Levothyroxine

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

  • Trouble sleeping / Headache Additional detail

    Policosanol

    Recorded for Policosanol in the same Natural Medicines adverse-effect record shown under Weight loss above.

    Levothyroxine

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

  • Itching Additional detail

    Policosanol

    “Orally, policosanol can cause pruritus or skin rash, but these events appear to be uncommon. In one clinical trial that included over 50 patients, one case of policosanol-associated skin rash was reported. In another study, 1 out of 40 patients treated with policosanol 10 mg daily reported pruritus.”

    Policosanol · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    3 sources cited
    1. 65369. Castano G, Fernandez L, Mas R, et al. Comparison of the efficacy, safety and tolerability of original policosanol versus other mixtures of higher aliphatic primary alcohols in patients with type II hypercholesterolemia. Int.J.Clin.Pharmacol.Res. 2002;22:5
    2. 95374. Castaño G, Fernández L, Mas R, Illnait J, Mesa M, Fernández JC. Comparison of the effects of policosanol and atorvastatin on lipid profile and platelet aggregation in patients with dyslipidaemia and type 2 diabetes mellitus. Clin Drug Investig. 2003;23(10 PubMed
    3. 100178. Wang HY, Jiao QP, Chen SY, et al. Efficacy and safety of policosanol plus fenofibrate combination therapy in elderly patients with mixed dyslipidemia: A randomized, controlled clinical study. Am J Med Sci. 2018;356(3):254-261. PubMed

    Levothyroxine

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

  • A skin rash Additional detail

    Policosanol

    Recorded for Policosanol in the same Natural Medicines adverse-effect record shown under Weight loss above.

    Levothyroxine

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

Reported for Policosanol but not commonly for Levothyroxine: stomach upset, drowsiness, bleeding or bruising and dizziness.

Effects for Levothyroxine come from the ADVERSE REACTIONS section of its FDA label; effects for Policosanol 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 — Policosanol Should Not Break It

At least one FDA label for a product containing Levothyroxine says to take it on an empty stomach. Most supplements — Policosanol 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 Policosanol 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 Policosanol 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 Policosanol 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 Policosanol 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 Policosanol as Part of a Dietary Supplement Product? Check It for Interactions

We hold 479 real supplement products containing Policosanol, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Policosanol. Even though Policosanol 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 Policosanol 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 Policosanol
Top half

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

What is Policosanol?

Policosanol
  • High cholesterol
  • Heart and blood vessel health
  • Leg pain from poor circulation (intermittent claudication)
  • Physical stamina and energy

Policosanol is a mix of waxy alcohols (mostly octacosanol) made from sugar cane or other plant waxes, and it is often marketed as a natural way to lower cholesterol. Early studies from Cuba showed strong cholesterol-lowering effects, but independent studies in other countries have mostly failed to confirm these benefits. Talk with your pharmacist or doctor before using it, especially if you take cholesterol medicine.

Wax extracted from sugar cane, beeswax, rice bran, or wheat germ · Tablets, capsules

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

Policosanol: dosing

There is no official or universally agreed-upon dose for policosanol. The amounts used in studies have varied, and the source of the wax can change how a product behaves. They can help you decide if it is appropriate for you and whether your cholesterol or heart condition needs proven treatment instead.

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

Read the full Policosanol 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 & Policosanol

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

0Major
242Moderate
0Minor
2,587No known interaction
242 Moderate 2,587 No interaction
Moderate

242 interactions

Showing 60 of 242 moderate interactions — see all 242 on the Policosanol page.

No interaction 2,587 drugs checked — show the list

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

Showing the 60 most looked-up of 2,587 medications checked with no known interaction — see the full Policosanol list.

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

Policosanol References

The 15 references that drive our Policosanol 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. Carbajal D, Arruzazabala ML, Valdes S, Mas R. Effect of policosanol on platelet aggregation and serum levels of arachidonic acid metabolites in healthy volunteers. Prostaglandins Leukot Essent Fatty Acids 1998;58:61-4.
  2. Arruzazabala ML, Valdes S, Mas R, et al. Comparative study of policosanol, aspirin and the combination therapy policosanol-aspirin on platelet aggregation in healthy volunteers. Pharmacol Res 1997;36:293-7. PubMed
  3. Valdes S, Arruzazabala ML, Fernandez L. Effect of policosanol on platelet aggregation in healthy volunteers. Int J Clin Pharmacol Res 1996;16:67-72.
  4. Greyling A, De Witt C, Oosthuizen W, Jerling JC. Effects of a policosanol supplement on serum lipid concentrations in hypercholesterolaemic and heterozygous familial hypercholesterolaemic subjects. Br J Nutr 2006;95:968-75. PubMed
  5. Abdul MI, Jiang X, Williams KM, et al. Pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects. Br J Clin.Pharmacol. 2010;69:508-15. PubMed
  6. Molina, Cuevas, V, Arruzazabala, M. L., Carbajal, Quintana D., Mas, Ferreiro R., and Valdes, Garcia S. Effect of policosanol on arterial blood pressure in rats. Study of the pharmacological interaction with nifedipine and propranolol. Arch Med Res 1998;29
  7. Castano G, Fernandez L, Mas R, et al. Comparison of the efficacy, safety and tolerability of original policosanol versus other mixtures of higher aliphatic primary alcohols in patients with type II hypercholesterolemia. Int.J.Clin.Pharmacol.Res. 2002;22:5
  8. Arruzazabala, M. L., Carbajal, D., Mas, R., Valdes, S., and Molina, V. Pharmacological Interaction Between Policosanol and Nitroprusside in Rats. J Med Food 2001;4(2):67-70. PubMed
  9. Castano G, Mas R, Gamez R, et al. Concomitant use of policosanol and beta-blockers in older patients. Int J Clin Pharmacol.Res 2004;24:65-77.
  10. Francini-Pesenti F, Brocadello F, Beltramolli D, et al. Sugar cane policosanol failed to lower plasma cholesterol in primitive, diet-resistant hypercholesterolaemia: A double blind, controlled study. Complement Ther Med 2008;16:61-65. PubMed
  11. Castaño G, Fernández L, Mas R, Illnait J, Mesa M, Fernández JC. Comparison of the effects of policosanol and atorvastatin on lipid profile and platelet aggregation in patients with dyslipidaemia and type 2 diabetes mellitus. Clin Drug Investig. 2003;23(10 PubMed
  12. Fernandez L, Mas R, Illnait J, Fernandez JC. Policosanol: results of a postmarketing surveillance study of 27,879 patients. Curr Ther Res 1998;59(10):717-22. DOI
  13. Wang HY, Jiao QP, Chen SY, et al. Efficacy and safety of policosanol plus fenofibrate combination therapy in elderly patients with mixed dyslipidemia: A randomized, controlled clinical study. Am J Med Sci. 2018;356(3):254-261. PubMed
  14. Xu K, Liu X, Li Y, Wang Y, Zang H, Guo L, et al. Safety and efficacy of policosanol in patients with high on-treatment platelet reactivity after drug-eluting stent implantation: two-year follow-up results. Cardiovasc Ther. 2016 Oct;34(5):337-42. doi: 10.1 PubMed
  15. Li C, Ding Y, Si Q, Li K, Xu K. Multiple functions of policosanol in elderly patients with dyslipidemia. J Int Med Res. 2020;48(7):300060520936082. 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 Policosanol and Levothyroxine Together: Common Questions

Is it safe to take Policosanol with Levothyroxine?
We do not list a known interaction between Policosanol 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 Policosanol 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 Policosanol 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 Policosanol 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 Policosanol and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Policosanol has documented interactions with 6 drug classes — 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 Policosanol interact with any other medications?
Yes. Policosanol has 242 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 — Policosanol 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

Policosanol 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 15 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Policosanol?

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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.