Senna Pods

What are senna pods?

Senna pods is the common name for the fruit of the plant Senna alexandrina Mill. 

The HMPC conclusions cover senna pod preparations that are obtained by drying and comminuting
(reducing into tiny pieces) the fruit. The dried, comminuted fruits may also be put in a solvent (such as
ethanol) to dissolve compounds and form an extract. All senna pod preparations are standardised to
contain a defined amount of anthraquinones, which are substances linked with the activity of senna
pods.

Herbal medicines containing senna pod preparations are usually available as herbal tea to be drunk,
and in liquid or solid forms to be taken by mouth.

Senna pod preparations may also be found in combination with other herbal substances in some herbal
medicines. These combinations are not covered in this summary.

What are its medicinal uses?

The senna pod preparations can be used short term for occasional constipation
and for bowel cleansing before medical procedures needing bowel emptying (such as bowel radiology
or colonoscopy).

Senna pod medicines should only be used in adults and adolescents over the age of 12 years. They
should not be taken for longer than one week for occasional constipation, and if symptoms continue or
get worse while taking the medicine, a doctor or pharmacist should be consulted. Usually it is sufficient to take senna pod medicines two to three times a week. For bowel cleansing, senna pod medicines
should be taken only once. Patients taking certain medicines should consult a doctor before taking
senna pod preparations at the same time.

How do senna pods work as a medicine?

Senna pod medicines contain anthraquinones. These stimulate bowel movements, encouraging the
bowels to empty. They also alter the absorption of water and salt from the bowels. This increases the
amount of water in the material in the gut and so softens it and allows it to pass along the gut more
easily.

What evidence supports the use of senna pod medicines?

The use of these senna pod medicines for occasional constipation and bowel
cleansing are based on their ‘well-established use’. This means that there are bibliographic data
providing scientific evidence of their effectiveness and safety when used in this way, covering a period
of at least 10 years in the EU.

In its assessment, the HMPC considered laboratory studies, experts reports, extensive clinical
experience as well as several studies in mostly elderly patients with long-term or severe constipation.
These studies compared senna medicines, taken with fibres, with other treatments for constipation
(such as lactulose). Overall, these studies showed that senna medicines taken with fibres were at least
as effective as the comparator at treating constipation.
Several clinical studies were also assessed which showed that senna pods were effective at bowel
cleansing.

What are the risks associated with senna pod medicines?

Side effects with senna pod medicines include allergic reactions, abdominal (belly) pain, spasm and
diarrhoea. Long-term use may cause colouration of the lining of the intestine, which usually resolves
when the patient stops taking the medicine, imbalance of water and salt in the body, presence of
proteins and blood in the urine and yellow or red-brown colour of the urine. The frequency of these
side effects is not known.
Senna pod medicines must not be taken by patients with blockages or stenosis (narrowing) of the
intestines, intestinal atony (loss of strength or movement in bowel muscles), appendicitis,
inflammatory bowel diseases (Crohn’s disease, ulcerative colitis), unexplained abdominal pain or
severe dehydration. They must also not be taken during pregnancy, when breastfeeding or by children
under 12 years of age.
Long-term use of laxatives like senna pods should be avoided, as use for more than a short time may
lead to the bowels not working properly and cause dependence on laxatives.