Spermidine is a polyamine that plays a crucial role in cellular health by activating autophagy, the body's process of removing damaged cells and maintaining healthy ones. As natural autophagy declines with age, supplementing with spermidine can rejuvenate this process. Benefits of spermidine include delaying aging, reducing age-related diseases, upregulating sirtuin 1, supporting liver health, providing anti-inflammatory effects, and promoting a healthy brain. Studies suggest that higher levels of spermidine are linked to a healthier, longer life.