Is there such a thing as a "slow release" lysine supplement? i feel as though perhaps the potential long-term renal issues from too much too quickly.

No, why taking it?: I'm not aware of slow-release lysine; even if it exists there is no evidence it would be safer. Again, there's only 1 report of kidney problems in a woman who took 3000 mg/day for 5 years but no proof lysine caused her problem. Millions have taken lysine safely. Why are you taking it? Keep your dose to 1500 mg/day ; have kidney function checked every 6 months if concerned but it should be safe.