Prunelax Extra Strength tablets is a laxative to keep your internal body moving and help relieve constipation symptoms in a natural way Prunelax is an effective and natural laxative made of natural Senna. To relieve bowel irregularity with a predictable overnight solution, take Prunelax. Prunelax is a laxative made of natural senna leaves. The active ingredient Sennosides B is naturally derived, effective, predictable and strong.