What is Sutherlandia?

Sutherlandia is a small shrub from southern Africa. Its dried leaves and stems are made into tea or pills. People take it for stress, low mood, poor appetite and weight loss.

In South Africa it is known as cancer bush, or kankerbos. That name comes from old use. No study shows that it treats cancer or HIV.

Human proof is thin. Its place in southern African home care is long and strong. Long use is not proof that a herb works.

How does Sutherlandia work?

No one knows how it works. Lab and animal tests point to a few ideas. None of them is proven in people.

The plant holds pinitol. This is a sugar that may help the body use blood sugar better. It also holds GABA, a brain chemical that can calm nerves.

Some call the herb an adaptogen. That word means a plant said to help the body cope with stress. This idea has not been tested well in people.

The same lab work raises a warning. The herb seems to slow liver enzymes that break down many drugs. If that happens in people, drug levels in the blood could rise or fall.

What forms does Sutherlandia come in?

Dried leaf tea is the oldest form. Tablets and capsules of milled leaf are now the most common.

You can also buy tinctures, which are drops made with alcohol, and loose leaf powder. Some products list the SU1 level, but many do not.

The herb is also sold in mixes with other plants. Mixes make it harder to know what caused a side effect.

Where it comes from:

Khoisan, Xhosa and Zulu healers have used this shrub for hundreds of years. Dutch settlers took it up as well, and named it kankerbos.

Old uses include fever, chest colds, poor appetite, stress and grief. Washes were used on wounds and sore eyes.

It became well known again in South Africa in the 1990s and 2000s. Many people used it during the HIV epidemic. That is why the first safety studies were run.

What does Sutherlandia help with?

• Stress and low mood: This is the most common modern use. Small short studies in healthy adults looked mainly at safety, not at mood, so we cannot say it helps. The herb holds GABA, a brain chemical that can calm nerves, but that is a lab finding only. If your low mood is deep or lasting, speak to a doctor.
• Poor appetite and weight loss: Traditional healers used it for people who were thin and eating poorly. Reports from users are mixed, and there is no good trial to back this up. Unplanned weight loss needs a medical check first, because the cause matters more than the remedy.
• Blood sugar control in type 2 diabetes: Animal work suggests it may lower blood sugar, probably through pinitol, a plant sugar. There is no reliable human trial. If you take diabetes medicine, adding this herb could push your sugar too low, so check with your doctor and test more often.
• Tiredness and general run-down feeling: Traditional use is strong here and modern proof is absent. It is often sold as a tonic or adaptogen, a plant said to help the body cope with stress. Ongoing tiredness can come from anaemia, thyroid trouble or infection, so get it checked.
• Fever and chest colds: This is one of the oldest recorded uses in southern Africa. No human trial has tested it for colds or fever. It should never replace treatment for a serious chest infection.
• Wound washing (on the skin): Cooled leaf tea was used as a wash for wounds and sore eyes. There is no modern evidence for this, and homemade washes are not sterile. Do not put it in your eyes, and see a nurse or doctor for any wound that is deep, dirty or spreading.

What are the side effects of Sutherlandia?

• Dry mouth
• Dizziness or light-headedness
• Loose stools or mild stomach upset
• Nausea
• Headache
• Trouble sleeping
• Loss of appetite in some people, which is the opposite of the usual reason for taking it
• Skin rash

Good to know:

Most reported effects are mild and settle when people stop taking it. They come from small, short studies and from user reports, so the true rate is unknown.

The bigger worry is not the side effects but the drug interactions and the risk in pregnancy. Long-term safety has not been studied, and the herb contains L-canavanine, an amino acid that can be toxic in large amounts.

How much Sutherlandia should you take?

• Recommended daily: There is no dose proven to work. The amounts below are what South African products and short safety studies have used, not a recommendation. Tablets or capsules of milled leaf: about 300 mg, once or twice a day. Tea: about a quarter of a teaspoon of dried leaf in a cup of hot water, once or twice a day. Start with the lowest amount. Never take more than the label says.
• Best time of day: Morning is the usual choice, because some people feel it makes sleep harder. If it makes you sleepy instead, take it in the evening.
• With or without food: Take it with food. This lowers the chance of nausea and loose stools.
• Time to effect: Nothing here is proven. Users who report a change in appetite or mood usually notice it in two to six weeks.
• How long to take it: Short use is what has been studied. Most safety studies ran for up to three months. If you notice no change after six to eight weeks, stop. Do not use it for months on end without a doctor checking on you, as long-term safety is unknown.