As centuries passed without any expedition returning proof of Penglai's physical existence, Daoist thought increasingly treated the island less as a literal destination to be sailed toward and more as a symbol of the state of immortality itself, the goal that the tradition's alchemical and meditative disciplines were meant to reach by other means. Waidan, external alchemy involving the compounding of elixirs from minerals and metals, and later neidan, internal alchemy cultivating and refining the practitioner's own vital energies through breath, visualization and meditation, both took the condition enjoyed by Penglai's immortals, deathlessness, freedom from ordinary appetite and suffering, effortless movement, as their explicit aim, even as practitioners increasingly understood the island itself as a poetic or visionary destination reached through inner transformation rather than a literal coastline any ship could find.
Penglai remained a productive motif well beyond strictly Daoist ritual contexts, recurring constantly in Chinese landscape painting, poetry and garden design, where artificial Penglai-inspired islands were built in imperial and elite gardens as miniature evocations of the immortal realm, and the name persists today attached to a real coastal city in Shandong province that claims identification with the legendary site, drawing tourists to a shoreline associated for over two thousand years with the promise of an island that can never quite be reached.