Cleavers Herb Side Effects and Safety: What to Know Before Trying It

Cleavers herb side effects are poorly studied. RxList calls cleavers possibly safe for most people by mouth, but it also says there is not enough information to set a dose, and EBSCO says the herb has not had meaningful safety testing.

So this guide stays careful. It covers cleavers tea side effects, reports of a rash or runny nose, extract and tincture cautions, pregnancy advice, and who should ask a doctor first.

Is Cleavers Safe?

Cleavers (Galium aparine) is a sticky, clinging plant also called goose grass, bedstraw, and catchweed. People have used it as a spring tea for a long time.

Long use is not the same as safety testing. RxList says cleavers is "possibly safe for most people when taken appropriately by mouth," yet it rates the evidence for its uses as insufficient (RxList). EBSCO adds that cleavers "has not undergone sufficient meaningful safety testing" (EBSCO).

So "gentle" is a folk word here, not a tested fact. Read on before you brew a cup.

Cleavers Herb Side Effects: What Is Reported

Neither RxList nor EBSCO lists specific cleavers side effects, and no large human safety study exists. That does not mean there are none. It means nobody has measured them well.

What we do see are reports and traditional cautions. Cleavers has a long folk use as a diuretic, which is an herb that makes people urinate more. So drinking a lot of it could affect fluids and salts, and that is why doctors ask about kidney disease and certain medicines.

Skin contact is another point. Fresh cleavers is covered in tiny hooked hairs, and many people report an itchy, scratchy feeling after handling the fresh plant. Wear gloves when you pick it.

Cleavers Tea, Aerial Parts, and Extract Side Effects

Most cleavers products use the aerial parts, which means the leaves, stems, and flowers above ground. EBSCO says the leaves and flowers are used medicinally.

Cleavers Tea Side Effects

We found no source that lists tea-specific side effects. A tea is the mildest form, but strength still varies with how much herb you use and how long you steep. See our cleavers tea recipe for the usual home method.

Stop the tea and call a doctor if you notice a rash, swelling, trouble breathing, or any reaction that worries you.

Cleavers Extract and Tincture Side Effects

An extract or tincture is a stronger form of the herb. RxList says there is not enough scientific information to set a proper dose, so no one can tell you a safe number of drops. Follow the product label and ask your pharmacist or doctor first.

Because a stronger form can act faster, anyone in the cautions below should be extra careful with extracts.

Can Cleavers Cause a Runny Nose or a Rash?

Some people ask whether cleavers can cause a runny nose or a rash. We found no study that shows this. A few people report cold-like symptoms or skin reactions after using it, but those reports are anecdotal.

Any plant can trigger an allergy in a sensitive person. So if you get a runny nose, itchy eyes, hives, or a rash after using cleavers, stop using it and tell your doctor. Seek urgent care for swelling of the face or throat, or trouble breathing.

Cleavers in Pregnancy and Breastfeeding

RxList says there is not enough reliable information about taking cleavers while pregnant or breastfeeding, and it advises avoiding use. EBSCO lists pregnant and nursing women among the groups for whom safety has not been shown.

So skip cleavers unless your doctor says otherwise.

Who Should Avoid Cleavers

• People who are pregnant or breastfeeding.
• Young children, since safety has not been shown (EBSCO).
• People with severe liver or kidney disease (EBSCO).
• People with diabetes, unless their doctor agrees, because RxList notes a concern that cleavers juice might affect diabetes.
• Anyone allergic to plants in the same family or who reacts to the plant.
• Anyone planning surgery, as a general rule for any herb. Ask your surgeon.

Cleavers Drug Interactions

RxList lists no drug interactions, but EBSCO names one: lithium. Because cleavers may act as a diuretic, EBSCO says people who take lithium should use it only under a doctor's supervision, since dehydration could be dangerous.

Interactions with other medicines are not well studied. If you take any prescription drug, ask your pharmacist before you use cleavers.

How to Use Cleavers More Safely

• Talk with your doctor or pharmacist first, above all if you take medicine or have a health condition.
• Buy from a maker that names the plant (Galium aparine) and the part used.
• Start with a weak, single cup and watch how you feel.
• Drink water as usual and do not use large amounts.
• Stop at the first sign of a reaction.

Want the traditional story? Read our guides to cleavers herb benefits and the cleavers and lymphatic system tradition. Our Cleavers Herb is a dried herb sold for traditional tea use.

Frequently Asked Questions

Final Thoughts

Cleavers has a long folk record but little modern safety testing. The honest summary is this: possibly safe for most adults in tea, not for pregnancy or nursing, with extra care for lithium, diabetes, and kidney or liver disease.

If you try it, keep it simple and short, and talk with your doctor first. A tea can never replace medical care.