All-purpose single-use medkit. Allows to handle injuries of different types and degrees of complexity. The medkit heals ~30% of your life and removes a chunk of bleeding and accumulated radiation.
Shadow of ChernobylEdit
Standard medkits can be purchased from nearly every trader, and can be found with some regularity on other stalkers, especially Military and Monolith. They only recover roughly a half of your health bar with each use, enough to counter one or two bullets, or a swipe from a powerful mutant. They offer very low protection to bleeding, so bandages must be taken in conjunction with them to counteract severe bleeding.
Medkits are slightly more effective in Clear Sky then in Shadow of Chernobyl. Again purchased from nearly every trader and picked up with some frequency from stalkers of any faction, they heal anywhere from 30 to 50% of your health bar, but also deal with light bleeding and scrapes that the original variety didn't touch.
Call of PripyatEdit
In Call of Pripyat, medkits are far more useful and valuable in the field. Not only are they not as commonly found as in the previous installments, they tend to be more expensive, and weight is more of a factor. As a trade off, they are far more potent at both recovering health and countering bleeding. Like all medicinal items in Call of Pripyat, however, it takes time to get the full effect from medkits, preventing one from simply spamming them to break through an ugly situation. Despite this, standard medkits are still the most common of the three; most stalkers have at least one in their inventory when looted.