You are recovering. Regen X restores X HP at the end of each of your turns for the stated duration.

Effects

  • Restore X HP at the end of your turn, where X is the Regen value
  • Total healing is X × duration — Regen 2 for 4 turns restores 8 HP
  • Regen is passive healing, so it also restores 💔 Cripple Threshold — divided evenly among all 6 limbs, rounded down, ignoring Crippled limbs. See 🏕 Long Rest
  • Robots do not benefit. They have no regenerative capability and are restored only by Fix and 🔩 Fix Malfunction — see 🤖 Robot

Sources

Applied by drink and food rather than by chems:

SourceRegenDuration
🚰 Dirty Water14 turns
🥤 Nuka-Cola24 turns
💧 Pure Water24 turns
🧊 Nuka-Cola Quantum44 turns
🍳 Deathclaw Omelette2in combat, until next 🏕 Long Rest