This potion looks almost identical to a Potion of Vitality. A DC 20 perception check reveals that something is wrong. If you have herbalism kit proficiency or  intentionally sample a tiny sip of it, you gain advantage on this perception check.

Make a DC 20 constitution save. On a success, this potion behaves like a regular Potion of Vitality as detailed below:

When you drink this potion, it removes any exhaustion you are suffering and cures any disease or poison affecting you. For the next 24 hours, you regain the maximum number of hit points for any Hit Die you spend. The potion's crimson liquid regularly pulses with dull light, calling to mind a heartbeat.

On a failure, the potions effect are reversed:

When you drink this potion, you gain 1d4 levels of exhaustion.

You are afflicted by the Torpor poison, provided you fail the additional saving throw.

For the next 24 hours, you regain the minimum number of hit points for any Hit Die you spend.

Notes: Exhaustion, Poisoned, Cures Disease, Removes Poison, Max HP from Hit Dice, Healing, Consumable