Standardized Senna Concentrate and Docusate Sodium. Works gently. Works overnight. Gently relieves constipation overnight. Purified Senna – Comfort Promise. The Senokot Laxative Comfort Promise – For your comfort, the active ingredient in Senokot Laxatives is always purified senna, manufactured to USP standards. Each tablet contains: Sodium (4 mg). Very low sodium.