Drug & supplement interaction

Palmitoylethanolamide (pea) + 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 Palmitoylethanolamide (pea) 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.

Know someone taking this? Share
Interaction report

Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Palmitoylethanolamide (pea) at all — not against Levothyroxine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Palmitoylethanolamide (pea) safety at a glance

Palmitoylethanolam... overall Use caution Generally well tolerated in studies, but long-term safety data are limited.
Pregnancy Avoid Not enough safety information, so avoid use during pregnancy.
Breastfeeding Avoid Not enough safety information, so avoid use while breastfeeding.

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

Still wondering about combining Levothyroxine and Palmitoylethanolamide (pea)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Palmitoylethanolamide (pea) 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.

  • Itching Additional detail

    Palmitoylethanolamide (pea)

    “Topically, applying a lotion containing PEA twice daily worsened pruritus and caused stinging, scaling, or reddening in 13% of patients with dry skin. However, these adverse effects did not occur more frequently than in patients applying the vehicle alone.”

    Palmitoylethanolamide (pea) · Natural Medicines adverse-effect record, reported in dry skin.

    1 source cited
    1. 106272. Visse K, Blome C, Phan NQ, Augustin M, Ständer S. Efficacy of body lotion containing N-palmitoylethanolamine in subjects with chronic pruritus due to dry skin: A dermatocosmetic study. Acta Derm Venereol. 2017;97(5):639-641. PubMed

    Levothyroxine

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

  • Nausea Additional detail

    Palmitoylethanolamide (pea)

    “Orally, PEA has been rarely reported to cause mild and transient gastrointestinal symptoms, such as nausea.”

    Palmitoylethanolamide (pea) · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    3 sources cited
    1. 93325. Indraccolo U, Barbieri F. Effect of palmitoylethanolamide-polydatin combination on chronic pelvic pain associated with endometriosis: preliminary observations. Eur J Obstet Gynecol Reprod Biol. 2010 May;150(1):76-9. PubMed
    2. 93327. Murina F, Graziottin A, Felice R, Radici G, Tognocchi C. Vestibulodynia: synergy between palmitoylethanolamide + transpolydatin and transcutaneous electrical nerve stimulation. J Low Genit Tract Dis. 2013 Apr;17(2):111-6.
    3. 106266. Papetti L, Sforza G, Tullo G, et al. Tolerability of palmitoylethanolamide in a pediatric population suffering from migraine: A pilot study. Pain Res Manag 2020;2020:3938640. PubMed

    Levothyroxine

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

Reported for Palmitoylethanolamide (pea) but not commonly for Levothyroxine: dry skin.

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

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

Overlapping uses

What Levothyroxine Is Prescribed For, and What Palmitoylethanolamide (pea) Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Levothyroxine is a prescription medicine with approved uses on its FDA label. Palmitoylethanolamide (pea) is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Levothyroxine is prescribed for: 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.

Palmitoylethanolamide (pea) has been studied for:

  • Depression studied, not established Palmitoylethanolamide (pea) has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Palmitoylethanolamide (pea) for depression

    It is unclear if oral PEA is beneficial for depression when used in combination with citalopram.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Levothyroxine on your own; if you are taking Palmitoylethanolamide (pea) for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) as Part of a Dietary Supplement Product? Check It for Interactions

We hold 97 real supplement products containing Palmitoylethanolamide (pea), each one broken down to its full ingredient list — and combination products often carry several ingredients besides Palmitoylethanolamide (pea). Even though Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea)
Top half

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

What is Palmitoylethanolamide (pea)?

  • Chronic pain
  • Nerve (neuropathic) pain
  • Inflammation
  • Low back and sciatica pain
  • General immune and recovery support

Palmitoylethanolamide (PEA) is a fat-like molecule made naturally in the body and studied mainly for pain and inflammation. Some research suggests it may help certain types of chronic and nerve pain, but the overall evidence is still limited and more high-quality studies are needed. It appears generally well tolerated, but talk with your pharmacist or doctor before starting it.

Not a plant; a fatty acid compound made in the body and found in some foods · Capsules, tablets, sublingual tablets, powders, and 'micronized' or 'ultramicronized' formulations

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

Palmitoylethanolamide (pea): dosing

There is no official, standardized dose of PEA. Studies have used a range of amounts and different formulations, including micronized and ultramicronized versions, which can affect how the body absorbs it.Because of this, the best approach is to follow the directions on the product label and start with the lowest suggested amount.

From our Palmitoylethanolamide (pea) monograph — the full record covers uses, side effects and every documented interaction.

Read the full Palmitoylethanolamide (pea) 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 & Palmitoylethanolamide (pea)

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Palmitoylethanolamide (pea) References

The 4 references that drive our Palmitoylethanolamide (pea) 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. Indraccolo U, Barbieri F. Effect of palmitoylethanolamide-polydatin combination on chronic pelvic pain associated with endometriosis: preliminary observations. Eur J Obstet Gynecol Reprod Biol. 2010 May;150(1):76-9. PubMed
  2. Murina F, Graziottin A, Felice R, Radici G, Tognocchi C. Vestibulodynia: synergy between palmitoylethanolamide + transpolydatin and transcutaneous electrical nerve stimulation. J Low Genit Tract Dis. 2013 Apr;17(2):111-6.
  3. Papetti L, Sforza G, Tullo G, et al. Tolerability of palmitoylethanolamide in a pediatric population suffering from migraine: A pilot study. Pain Res Manag 2020;2020:3938640. PubMed
  4. Visse K, Blome C, Phan NQ, Augustin M, Ständer S. Efficacy of body lotion containing N-palmitoylethanolamine in subjects with chronic pruritus due to dry skin: A dermatocosmetic study. Acta Derm Venereol. 2017;97(5):639-641. 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 Palmitoylethanolamide (pea) and Levothyroxine Together: Common Questions

Is it safe to take Palmitoylethanolamide (pea) with Levothyroxine?
We do not list a known interaction between Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to 2 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 Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea) 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.
Are Palmitoylethanolamide (pea) and Levothyroxine used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Palmitoylethanolamide (pea) in each. That is a conversation for your prescriber, especially if Levothyroxine is being adjusted to a target.
Does Levothyroxine interact with any supplements?
Yes. Levothyroxine has documented interactions with 50 supplements in our database — Palmitoylethanolamide (pea) 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 Palmitoylethanolamide (pea)?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.