This mod reduces the rate of passive health regeneration from Life Giver and Solar Powered by 90%, bringing them in line with survival difficulty. In the vanilla game, passive regeneration was 0.5% of your max HP per second from each of those perks, so with both of them you regenerate 1% of your hit points each second. On normal difficulties that's not a big deal, but on Survival all other sources of healing take 10x as long. That means that, for example, passive health regeneration is faster than stimpaks. Other mods already existed that removed passive health regeneration entirely, but none that keep regeneration and balance it to survival.

This mod does not reduce the rate of regeneration from the magazine, as that is already 0.01% of your max HP, and that's as low as it can go. This means the maximum health regeneration is 0.11% of your max HP, enough to fill your HP from 1% to 100% in 15 minutes of real-world time, as opposed to the 1.01% you could get previously, which would refill your HP from 1% to 100% in 1 minute and 39 seconds.