Does it work?


Can Sceletium be used to relieve stress?


A number of South African plants are being investigated as sources of herbal remedies. A small number of Sceletium species are regarded as having the most promise as commercial herbal remedies. Sceletium plantations have been developed, extracts are being researched and new commercial products are regularly appearing on the market.

The most widely used of these species is Sceletium tortuosum, known locally as kanna. The scientific name comes from the Latin for skeleton – the dried leaves have a skeletal appearance.

The local name literally means “something to chew”, and refers to how the plant is chewed for its effects. The plant is also fermented to give a form that is said to be stronger, even leading to intoxication.

Commercial interest in Sceletium has focused on its potential as a natural stress reliever and mood elevator. Widespread use of antidepressants has suggested that a market exists for natural remedies.


Chemical analyses of Sceletium started more than 100 years ago. Various types of compounds called alkaloids have been identified in the plants and found to have medicinal effects. However, most of the research on the alkaloids has focused on their identification and not their effects in humans.

Research has confirmed that the traditional fermentation process changes the quantities and relative concentrations of the alkaloids. Also, the alkaloid concentration found in dried plant material varies considerably, ranging from 0.05 to 2.3 per cent. This means that different products are likely to have widely varying amounts of active ingredients.

Laboratory studies have found that Sceletium alkaloids are selective serotonin reuptake inhibitors (SSRIs). Thus, they have the same action as pharmaceutical SSRIs such as Prozac.

This finding has stimulated much interest from both researchers and promoters of Sceletium products. Animal studies have found that Sceletium can improve mood and reduce anxiety-related behaviours. However, these studies were carried out without the use of control groups.

Last month, the first animal study with a control group found conflicting results. At low doses, the animals given Sceletium appeared more calm, but at higher doses there was evidence of increased excitation.

In humans, only a small number of case reports have been published. These reported improvements in generalised anxiety and depression in three patients. No controlled research in humans was located, and it is needed before Sceletium can be recommended.


Anecdotal reports have noted that Sceletium can cause nausea and headaches, but adverse effects are not common. Safety studies carried out in animals recently found no adverse effects. No safety studies have been conducted with humans, nor have the effects of taking Sceletium for longer periods been examined.


Commercial products made from Sceletium tortuosumare increasingly available. The research conducted to date has confirmed their potential to have beneficial effects on mood.

However, this research is still in its infancy and practically none has been done in humans. High-quality studies are needed to determine whether Sceletium is effective or safe, and, if so, what the best dosage would be.

The herb is used traditionally for everyday levels of stress and tension, not as a treatment for mental-health difficulties. Whether it may have a role in helping people with depression and anxiety has not been investigated.

Anyone struggling with such conditions should talk to someone about how they are feeling, and pursue the various avenues of help available, as appropriate to their symptoms.

Dónal OMathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics, and is a senior lecturer in the school of nursing, Dublin City University