Difference Between Senna Products
"Senna S," "Senna Laxative," and "Senna Plus" are different commercial formulations of the same active ingredient (sennosides), with "Senna Plus" containing an added stool softener (docusate sodium), though evidence suggests the combination offers no advantage over sennosides alone. 1, 2
Product Formulations
Senna or Senna Laxative (Plain Sennosides)
- Contains sennosides alone (typically 8.6 mg per tablet) as the sole active ingredient 3
- Works as a stimulant laxative by stimulating colonic peristalsis and secretion through prostaglandin E2 production 3
- Produces bowel movement in 6-12 hours 1
- Recommended starting dose is 8.6-17.2 mg daily (1-2 tablets), with maximum of 4 tablets twice daily 3
Senna Plus (Sennosides + Docusate)
- Contains sennosides 8.6 mg PLUS docusate sodium 50 mg per tablet 1
- Combines a stimulant laxative (sennosides) with a stool softener (docusate) 1
- Marketed as providing dual action: stimulation plus softening 1
Clinical Evidence: Which Is Better?
The addition of docusate to sennosides provides no clinical benefit and may actually reduce effectiveness. 2
Key Study Findings
- A direct comparison in hospitalized cancer patients found that sennosides alone produced MORE bowel movements than sennosides plus docusate 2
- In patients admitted for symptom control, 62.5% on sennosides alone had frequent bowel movements versus only 32% on the combination (p < 0.05) 2
- The combination group required more rescue interventions (57% vs 40%) with suppositories, enemas, or lactulose 2
- Cramping rates were identical (10% in both groups), showing no benefit from adding docusate 2
Guideline Recommendations
- The 2023 AGA-ACG guidelines recommend senna (sennosides alone) for chronic constipation, with no mention of combination products 3
- NCCN guidelines specifically state that docusate has not shown benefit and is not recommended for constipation 4
- ESMO guidelines do not recommend docusate-containing products for constipation management 4
Practical Recommendations
Start with plain sennosides (Senna or Senna Laxative), not Senna Plus:
- Begin with 8.6-17.2 mg daily (1-2 tablets of 8.6 mg strength) 3
- Take in the evening or at bedtime for morning bowel movement 3
- Titrate upward based on response and tolerability 3
- If cramping or abdominal pain occurs, reduce the dose rather than adding docusate 3
Important Caveats
- 83% of patients in clinical trials reduced their senna dose due to side effects at higher doses (1 g daily), so start low 3
- Abdominal cramping is dose-dependent—use the lowest effective dose 3
- While studied for 4 weeks in trials, longer-term use is probably appropriate though long-term safety data are limited 3
- Avoid in pregnancy as chemically similar substances may have adverse effects 3
Cost Consideration
All senna formulations cost less than $50 per month, making cost differences negligible 3