The final years of Starkey's life were devoted to resurrecting his medical practice and manufacturing income-producing medicines. However, he never wandered far from his chymistry lab and his quest for Van Helmont's alchahest or the philosophers' stone. No doubt he continued his search for the perfect liquor alchahest, a medicinal solvent whose purpose was similar to theriac, an antidotal compound that was consumed to preserve health and prevent illness. Starkey's success in producing his alchahest was limited, and his quest for the philosophers' stone never came to fruition. Although he continued to produce medical treatises, three political pamphlets that he wrote in 1660 along with public disputes he engaged in with other medical practitioners and the Royal College of Physicians further tainted his career.