Herbal Supplement That Supports Healthy Blood Pressure Levels Already in the Normal Range. Coleus is the source of a unique substance known as forskolin. Forskolin helps naturally increase a signaling molecule in our bodies called cyclic adenosine monophosphate or cAMP. In turn cAMP supports blood vessel relaxation and healthy heart muscle contractions. . Research also shows that forskolin may also support the smooth muscle of the lungs for healthy breathing and bronchial function.