Senna’s Pro-Motility Effects: Clinical Study Review

Senna (the leaf of Senna alexandrina) has been used for centuries as a gentle herbal laxative. Recent clinical trials now quantify exactly how its active compounds—anthraquinone glycosides—stimulate colonic activity. In this post, we’ll review the landmark 1989 study by Frexinos et al., explore the mechanism of action, discuss dosing considerations, and explain how Planta Lax Tea harnesses these effects for reliable, overnight relief.

Key Study: Frexinos J et al., Dig Dis Sci. 1989;34(2):214–219

  • Design: Double-blind, randomized, placebo-controlled
  • Subjects: 12 healthy volunteers
  • Intervention: Single oral dose of 17 mg sennosides (standardized senna extract)
  • Outcome: Colonic propulsive activity increased by 80 % over baseline, peaking at 6–12 hours post-dose.

How Senna Works

Senna’s anthraquinones are converted by gut bacteria into active metabolites that:

  1. Stimulate Enteric Nervous System: Enhance peristaltic contractions along the colon.
  2. Inhibit Water & Electrolyte Absorption: Increase fluid content in stool, softening consistency.
  3. Synergize with Other Botanicals: In Planta Lax Tea, cascara bark and chamomile modulate the effect for comfort.

Dosage & Safety

Based on clinical data and pharmacopeial guidelines:

  • Typical Dose: 1–2 g of senna leaf equivalent (one sachet of Planta Lax Tea delivers ~1.2 g total herb blend).
  • Onset: 6–12 hours—ideal for evening use to avoid daytime urgency.
  • Precautions: Not recommended for children under 12, pregnant or nursing women, or daily use beyond 7 days without medical supervision.

Why Choose Planta Lax Tea?

Our formula mirrors the proven clinical dose of senna while blending chamomile and cascara to:

  • Soften and stimulate gently
  • Reduce cramping via anti-spasmodic actions
  • Support gut flora balance with mild prebiotic fibers

References

  • Frexinos J et al. Colonic propulsive activity after single-dose sennosides. Dig Dis Sci. 1989;34(2):214–219. doi:10.1007/BF01536053
  • FDA OTC Laxative Monograph. U.S. Food & Drug Administration, 2002.

Next Steps

In our next post, we’ll explore chamomile’s role in reducing intestinal inflammation. Stay tuned →