Drug & supplement interaction

Chlorophyll + 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 Chlorophyll 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
Facebook Post Reddit Email
On this page
Interaction report

Chlorophyll 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 Chlorophyll 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.

Chlorophyll safety at a glance

Chlorophyll overall Use caution Generally well tolerated in short-term use, but high-quality safety data are limited.
Pregnancy Avoid Not enough reliable safety information, so it is best avoided during pregnancy.
Breastfeeding Avoid Safety during breastfeeding is unknown, so avoid unless your doctor advises otherwise.

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

Still wondering about combining Levothyroxine and Chlorophyll? 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. Chlorophyll has documented interactions with 2 drug classes — the most serious being methotrexate (trexall, others) (moderate) and photosensitizing 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

Chlorophyll Does Interact With Other Medications

Chlorophyll has 337 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 337 No known interaction 2,493 (incl. Levothyroxine)
Taking anything else?

Check Another of Your Medications Against Chlorophyll

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

What to actually watch for

No Interaction Found — But Data Suggests Chlorophyll and Levothyroxine May Share a Side Effect

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.

  • A skin rash Additional detail

    Chlorophyll

    “Topically, chlorophyll cream has been reported to cause dermatitis. Orally, chlorophyll can cause photosensitization. Certain carotenoids such as beta-carotene and canthaxanthin seem to prevent or lessen the photosensitivity that results from taking chlorophyll. Oral consumption of chlorophyll has been associated with the development of pseudoporphyria in case reports.”

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

    4 sources cited
    1. 41912. Belen'kii, G. B. and Krikun, B. L. [Treatment of herpes simplex and herpes zoster by chlorophyll preparations]. Sov.Med. 1971;34(1):151-152.
    2. 1326. Mathews-Roth MM. Carotenoids in erythropoietic protoporphyria and other photosensitivity diseases. Ann N Y Acad Sci, 1993; 691:127-38. PubMed
    3. 93892. Rossi E, Borchard K, Cole JM. Pseudoporphyria following self-medication with chlorophyll. Australas J Dermatol. 2015 Feb;56(1):47-8. PubMed
    4. 97933. Zhao CY, Frew JW, Muhaidat J, et al. Chlorophyll-induced pseudoporphyria with ongoing photosensitivity after cessation - a case series of four patients. J Eur Acad Dermatol Venereol 2016;30(7):1239-42. PubMed

    Levothyroxine

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

Reported for Chlorophyll but not commonly for Levothyroxine: sun sensitivity.

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

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

Chlorophyll has been studied for:

  • Constipation studied, not established Chlorophyll has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Chlorophyll for constipation

    Although there has been interest in using oral chlorophyll for constipation, there is insufficient reliable information about the clinical effects of chlorophyll for this purpose.

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 Chlorophyll for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Chlorophyll 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 Chlorophyll 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 Chlorophyll 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 Chlorophyll as Part of a Dietary Supplement Product? Check It for Interactions

We hold 996 real supplement products containing Chlorophyll, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chlorophyll. Even though Chlorophyll 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 Chlorophyll 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 Chlorophyll
Top 25%

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

What is Chlorophyll?

Chlorophyll
  • Body and breath odor reduction
  • Wound healing (topical)
  • Detoxification
  • Antioxidant support
  • Skin health

Chlorophyll is the green pigment found in plants and algae, and supplements often use a stable form called chlorophyllin. It is most studied for reducing body and fecal odor and as a topical wound aid, but evidence for popular claims like detox and weight loss is weak. It is generally well tolerated for most adults, but talk with your pharmacist or doctor before starting, especially if you are pregnant or breastfeeding.

Green parts of plants and algae (commonly alfalfa and algae sources) · Capsules, tablets, liquid drops, topical ointments, and chlorophyllin (a semi-synthetic form)

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

Chlorophyll: dosing

There is no official, standardized dose of chlorophyll or chlorophyllin for most uses. Products vary widely in their strength and form, from liquid drops to capsules.The best approach is to follow the directions on the product label and not take more than recommended.

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

Read the full Chlorophyll 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 & Chlorophyll

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

0Major
337Moderate
0Minor
2,492No known interaction
337 Moderate 2,492 No interaction
Moderate

337 interactions

Showing 60 of 337 moderate interactions — see all 337 on the Chlorophyll page.

No interaction 2,492 drugs checked — show the list

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

Showing the 60 most looked-up of 2,492 medications checked with no known interaction — see the full Chlorophyll list.

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

Chlorophyll References

The 5 references that drive our Chlorophyll 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. Mathews-Roth MM. Carotenoids in erythropoietic protoporphyria and other photosensitivity diseases. Ann N Y Acad Sci, 1993; 691:127-38. PubMed
  2. Belen'kii, G. B. and Krikun, B. L. [Treatment of herpes simplex and herpes zoster by chlorophyll preparations]. Sov.Med. 1971;34(1):151-152.
  3. Brooks SL, Sanders J, Seymour JF, Mellor JD. A case of delayed methotrexate clearance following administration of a complementary medication containing chlorophyll. J Oncol Pharm Pract. 2014 Jun;20(3):225-8. PubMed
  4. Rossi E, Borchard K, Cole JM. Pseudoporphyria following self-medication with chlorophyll. Australas J Dermatol. 2015 Feb;56(1):47-8. PubMed
  5. Zhao CY, Frew JW, Muhaidat J, et al. Chlorophyll-induced pseudoporphyria with ongoing photosensitivity after cessation - a case series of four patients. J Eur Acad Dermatol Venereol 2016;30(7):1239-42. 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 Chlorophyll and Levothyroxine Together: Common Questions

Is it safe to take Chlorophyll with Levothyroxine?
We do not list a known interaction between Chlorophyll 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 Chlorophyll and Levothyroxine have any of the same side effects?
Yes — our sources link each of them separately to one 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 Chlorophyll 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 Chlorophyll 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 Chlorophyll 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 Chlorophyll in each. That is a conversation for your prescriber, especially if Levothyroxine is being adjusted to a target.
How was the Chlorophyll and Levothyroxine combination checked?
Interactions in our licensed database are recorded against drug classes. Levothyroxine is filed under 3 classifications, and Chlorophyll has documented interactions with 2 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 Chlorophyll interact with any other medications?
Yes. Chlorophyll has 337 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 — Chlorophyll 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

Chlorophyll 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 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Levothyroxine and Chlorophyll?

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.