Senna is a natural laxative derived from the Senna alexandrina plant. It is approved for the short-term treatment of occasional constipation. This herbal remedy stimulates the intestines, promoting bowel movements to alleviate discomfort. Senna is available over-the-counter for relief from irregularity.
Typical Onset of Senna’s Effects
Senna produces a bowel movement within 6 to 12 hours after it is taken. This timeframe makes it common to take senna at bedtime, allowing it to work overnight for a morning bowel movement.
Factors influencing how quickly senna works include individual metabolism and constipation severity. While most forms, like tablets or teas, fall within the 6-12 hour range, liquid formulations taken on an empty stomach can act more rapidly, sometimes within 1 to 3 hours. Taking senna with food does not significantly alter its effectiveness but can affect the onset time for some individuals.
How Senna Works and Proper Administration
Senna operates as a stimulant laxative. Its active compounds, sennosides, are not absorbed in the upper digestive tract. Gut bacteria in the colon metabolize these sennosides into active substances, primarily rheinanthrone. This active metabolite irritates the bowel lining, increasing fluid secretion into the colon and stimulating muscle contractions (peristalsis) to move stool through the intestines.
It is advised to start with the lowest effective dose. Senna is available in various forms, including tablets, liquids, powders, and chewable pieces. Adults and children aged 12 and over typically begin with 7.5 mg to 15 mg once daily at bedtime. Follow the specific dosing instructions on the product packaging or from a healthcare professional. Staying well-hydrated by drinking plenty of fluids, such as 6 to 8 glasses of water daily, is also recommended when using senna to prevent constipation from worsening.
Safety and Precautions for Senna Use
Senna is safe for short-term use but can cause temporary side effects. Common effects include abdominal pain, discomfort, cramps, and diarrhea. Some individuals may also notice a harmless yellow-brown or reddish discoloration of urine.
Prolonged or excessive use of senna carries risks. Using it for longer than one week, or exceeding recommended doses, can lead to laxative dependence, impairing natural bowel function. Long-term use can also result in an electrolyte imbalance, where levels of minerals like potassium become too low. Severe electrolyte imbalances can lead to muscle weakness, heart rhythm problems, and other health concerns.
Senna is not suitable for everyone. It should not be used by individuals with severe stomach pain, inflammatory bowel conditions like Crohn’s disease or ulcerative colitis, appendicitis, or intestinal blockages. Pregnant or breastfeeding individuals should consult a healthcare professional before using senna. Seek medical attention if constipation persists after three days of using senna, if severe side effects occur, or if considering long-term use.