What to Avoid With Chlorophyll for Safe Supplementation

January 13, 2026 •

3 min read

While often marketed as a natural wellness product, a 2015 study noted rare cases of chlorophyll-induced pseudoporphyria and ongoing photosensitivity after cessation. Understanding what to avoid with chlorophyll, such as specific medications and overconsumption, is crucial for safe supplementation and minimizing risks.

Quick Summary

This article outlines essential precautions for taking chlorophyll, detailing specific medication interactions, potential side effects, and who should exercise caution or avoid it entirely. It covers digestive issues, increased sun sensitivity, risks for pregnant or breastfeeding women, and the importance of professional consultation.

Key Points

Avoid Specific Medications: Never take chlorophyll with methotrexate, as it can dangerously increase the drug's effects.
Be Wary of Sun Exposure: Chlorophyll can increase photosensitivity; avoid excessive sun and use sunscreen to prevent sunburn.
Take Caution with Pregnancy/Breastfeeding: The safety of chlorophyll supplements for pregnant and breastfeeding individuals has not been established, so it is best to avoid.
Monitor for Digestive Side Effects: Overconsumption, particularly of liquid chlorophyll, can lead to nausea, cramping, and diarrhea.
Separate from Other Medications: Take chlorophyll at a different time than other medications to avoid potential interactions and absorption issues.
Understand Discoloration: Be aware that green, yellow, or black discoloration of stool and urine can occur, which is harmless.
Consult a Doctor: Always talk to a healthcare provider before starting any new supplement, especially if you have chronic health conditions or are on medication.

Who Should Avoid Chlorophyll?

Although considered safe for most people in moderation, certain individuals and medical conditions warrant caution or complete avoidance of chlorophyll supplementation. Consulting a healthcare provider is always the best first step before starting any new supplement regimen.

People on Specific Medications

Chlorophyll can interact with several types of medications, potentially altering their effectiveness or increasing side effects. Some of the most notable interactions include:

Photosensitizing Drugs: Certain medications, including some antibiotics (like ciprofloxacin) and acne treatments, increase skin sensitivity to sunlight. Since chlorophyll can also increase photosensitivity, combining them dramatically raises the risk of severe sunburn, rashes, or blisters.
Methotrexate: This drug, used to treat conditions like psoriasis and rheumatoid arthritis, is processed slowly by the body. WebMD notes that chlorophyll may slow down this process even further, increasing methotrexate levels and raising the risk of adverse side effects.
Blood Thinners (e.g., Warfarin): Some chlorophyll products contain vitamin K, which can interfere with the effectiveness of blood-thinning medications. Anyone on blood thinners should consult their doctor before taking chlorophyll.

Pregnant or Breastfeeding Individuals

The safety of chlorophyll supplements for pregnant and breastfeeding women has not been sufficiently studied. Healthcare professionals advise avoiding supplementation in these cases to err on the side of caution. Opting for chlorophyll-rich foods like spinach and kale is a safer alternative.

Those with Digestive Disorders

Individuals prone to diarrhea or those with conditions like Small Intestinal Bacterial Overgrowth (SIBO) should proceed with caution. Excessive amounts of chlorophyll can cause digestive upset, including nausea, stomach cramps, and diarrhea, especially in liquid form.

Side Effects to Watch For

Even for those without contraindications, certain side effects can occur, particularly with overconsumption.

Photosensitivity: As mentioned, chlorophyll can make skin more sensitive to the sun. Always use sun protection and limit prolonged sun exposure when supplementing with chlorophyll.
Digestive Issues: The most common side effects are mild stomach discomfort, including nausea, cramping, and loose stools.
Discoloration: The strong green pigment can harmlessly discolor urine, stool, or the tongue. This can cause unnecessary alarm if mistaken for a more serious condition like gastrointestinal bleeding.

Potential Chlorophyll Interactions Table

This table summarizes potential interactions and precautions to help you make an informed decision.


Interaction Type	Examples	What to Avoid	Source
Medication Interaction	Methotrexate (psoriasis/cancer drug), some antibiotics (e.g., Cipro)	Combining chlorophyll with photosensitizing medications or methotrexate can be risky. Always check with a doctor.
Photosensitivity	Prolonged sun exposure, tanning beds	Avoid excessive sun exposure, wear protective clothing, and use sunscreen.
Overconsumption	Exceeding recommended dosage, especially with liquid supplements	Taking more than the recommended dosage can increase side effects like diarrhea and nausea.
Pregnancy/Breastfeeding	All chlorophyll supplements	Until more research confirms safety, avoid supplementation and stick to dietary sources.
Gastrointestinal Issues	High doses, especially liquid forms	Start with a small dose and take with food if you have a sensitive stomach.

The Best Way to Get Chlorophyll

For most people, the safest and most beneficial way to increase chlorophyll intake is through a balanced diet rich in leafy green vegetables, such as spinach, kale, and broccoli. This method also provides essential vitamins, minerals, and fiber, without the risks associated with highly concentrated supplements. For those who choose to supplement, it is best to leave at least a few hours between taking chlorophyll and any other medications to prevent potential absorption issues.

Conclusion

While chlorophyll is widely promoted online for its potential health benefits, it is not without risks, especially in supplement form. It is vital to understand what to avoid with chlorophyll, including potential interactions with medications like methotrexate and photosensitizing drugs, excessive sun exposure due to increased sensitivity, and supplementation during pregnancy or breastfeeding. Starting with a low dose and listening to your body can help minimize side effects like digestive upset. The safest way to reap its nutritional benefits remains a diet rich in green vegetables. Always consult a healthcare professional before adding any new supplement to your routine.

Visit this comprehensive guide from Oregon State University's Linus Pauling Institute for further reading on chlorophyll and chlorophyllin.

Frequently Asked Questions

No, you should avoid taking chlorophyll with certain antibiotics that cause photosensitivity, as this combination can increase your risk of severe sunburn and skin reactions.

Yes, taking chlorophyll can increase your skin's sensitivity to sunlight, a condition known as photosensitivity. It is important to use sun protection and limit sun exposure to prevent sunburn.

Pregnant or breastfeeding individuals, those on specific medications like methotrexate or photosensitizing drugs, and people with severe digestive issues should avoid or consult a doctor before taking chlorophyll.

Common side effects include mild digestive issues such as nausea, stomach cramps, and diarrhea, as well as harmless discoloration of urine or stool.

Yes, taking excessive amounts of chlorophyll, especially in liquid form, can increase the likelihood and severity of side effects like gastrointestinal discomfort and diarrhea.

It is generally advised to leave at least one to two hours between taking chlorophyll supplements and other medications to avoid potential interference with absorption.

The safest and most beneficial way to increase chlorophyll intake is from natural food sources like green vegetables, as this provides additional nutrients and fiber without the risks of concentrated supplements.