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Overview: Coleus is a plant called Coleus forskohlii. It is available as an over-the-counter dietary supplement, most often as capsules or tablets made from the root of the plant. People take coleus for many reasons, such as to help with weight loss, asthma, and heart or thyroid conditions, although its benefits are not well defined. Side effects are not well studied, but they include diarrhea, nausea, stomach pain, and dizziness. Check with your health care provider before using coleus, especially if you have any health conditions or take any medicines.

Uses

What is coleus used for?

Coleus (Coleus forskohlii) is used for various reasons. Some common reasons for taking coleus supplements include the following, although research has not shown clear benefits for any of these uses.

Coleus should not be used in place of treatment prescribed by your health care provider for conditions such as asthma, glaucoma, high blood pressure, heart disease, or thyroid problems. Delaying proven medical treatments can cause permanent harm, such as vision loss in glaucoma.

Note: The FDA has not reviewed coleus for safety and effectiveness. Learn more about dietary supplements here.

How does coleus work (mechanism of action)?

Coleus is a plant called Coleus forskohlii, which is also called Plectranthus barbatus, Indian coleus, or makandi. Coleus supplements are usually made from the root of the plant.

Coleus contains a natural chemical called forskolin that is thought to be mainly responsible for its effects. Forskolin activates an enzyme in the body called adenylyl cyclase. This raises the level of a messenger chemical inside cells called cyclic AMP (cAMP), which then triggers many effects throughout the body.

These effects may include relaxing blood vessels and lowering blood pressure, relaxing the airways in the lungs, lowering pressure inside the eye, slowing the clumping of platelets (blood cells that help form clots), releasing stored fat from fat cells, and increasing thyroid hormone release. However, these effects were mainly seen in lab and animal studies, and benefits in people are not well defined.

Coleus has been studied for weight loss in people, but there’s not enough evidence to know if coleus can actually help people lose weight. In a small 12-week study of women who were mildly overweight, coleus did not cause weight loss, although it may have helped prevent weight gain.

Studies of forskolin for glaucoma have had mixed results, and very little research has been done in people with glaucoma.

Herbal products such as Coleus naturally contain many different chemicals, such as forskolin. The amounts of each chemical in a specific coleus product may vary. Different amounts of forskolin may change the effects of coleus on the body.

How should I store coleus?

You should store coleus according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of coleus?

There is not enough research to know what the common side effects of coleus may be. Based on what is known about how Coleus works and on some reports, possible side effects are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.

  • Nausea, diarrhea, or stomach discomfort
  • Headache
  • Dizziness or lightheadedness
  • Flushing
  • Fast heartbeat

There may be other side effects of Coleus that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of coleus?

While less common, the most serious side effects of coleus are described below, along with what to do if they happen.

Severe Allergic Reactions. Coleus may cause allergic reactions, which can be serious. Stop using coleus and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching or skin rash
  • Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use Coleus?

Allergies to Ingredients. People who are allergic to any of the following should not use coleus.

  • Coleus
  • Coleus forskohlii
  • Forskolin
  • Indian coleus
  • Makandi
  • Plectranthus barbatus
  • Other plants in the mint (Lamiaceae) family
  • Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific coleus products they stock.

What should I know about coleus before using it?

Coleus is a dietary supplement. It cannot be marketed to treat or cure a disease.

Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.

Keep coleus out of the reach of children.

Herbal products, such as coleus, naturally contain many different chemicals. The amount of each chemical in a specific coleus product can change for many reasons, including the area where the plant was grown, the weather during growth, the time of year when it was harvested, and the way that the plant was processed after it was harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability.

Coleus supplements are usually made from the root of the plant, but products may vary. Coleus is available in different forms, including capsules, tablets, and extracts. Each of these forms may contain different amounts of the chemicals that are naturally found in the plant. Many products are labeled as standardized to 10% forskolin.

Testing of coleus supplements sold to consumers has found that many products did not contain the amount of forskolin stated on the label, and some contained no detectable forskolin at all.

The FDA has not tested coleus products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.

What should I tell my health care provider before using coleus?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. Also tell them if you have an upcoming surgery. Sharing this information will help your health care provider know if this or other supplements are right for you.

In particular, make sure that you discuss any of the following.

Other Medicines and Supplements. Coleus may interact with other medicines and supplements. Before using coleus, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • Low blood pressure or high blood pressure treated with medicine
  • Heart problems or irregular heartbeat
  • Thyroid problems
  • Bleeding problems
  • Liver problems
  • Kidney problems, including polycystic kidney disease
  • Glaucoma or other eye conditions

Planned Surgery or Procedure. If you are scheduled for a surgery or dental procedure, tell your health care provider that you take coleus. They may ask you to stop taking it beforehand because it could raise the risk of bleeding.

Pregnancy. It is not known if or how coleus could affect pregnancy or harm a fetus. If you are pregnant or plan to become pregnant, check with your health care provider before using this or any supplement.

Breastfeeding. It is not known if coleus passes into breast milk. If you are breastfeeding or planning to breastfeed, check with your health care provider before using this or any supplement.

Interactions

Does coleus interact with foods or drinks?

There are no known interactions between coleus and foods or drinks.

It is unknown if drinking alcohol will affect coleus.

Does Coleus interact with medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are taking warfarin, which is a blood thinner.

Coleus may alter the blood levels of some medicines. Tell your health care provider about all medicines that you take or have recently taken.

The interactions between coleus and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with Coleus is incomplete. Always check with your health care provider before taking Coleus with any medicines.

Overdose/Missed Dose

What should I do if I accidentally use too much Coleus?

If you or someone else has used too much Coleus, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Coleus comes in a range of doses and forms. Read the product label closely, and speak to a health care provider about how to use Coleus safely. Do not take double or extra doses, even if you miss a dose.