Like all Lunar items, the Spinel Tonic has a powerful effect and drawback.
Activating this item gives the player +100% damage, +70% attack speed, +20 armor, +50% maximum health, increases movement speed by +30%, and increases their passive health regeneration by +300%. This effect lasts for 20 seconds, and has a base cooldown of 60 seconds. It should be noted that the Tonic does not increase the regeneration rate of shields. As such, if a player knows they will be using this equipment at some point in their run, it is highly advised to avoid obtaining Transcendence.
This effect also adds a visual filter to the screen, displacing the outlines of items and other HUD effects, such as the Huntress' target reticle and the similar reticle of the Royal Capacitor. It also turns the screen very slightly fish-eyed, blue, and grainy, though these effects are fairly minor.
Upon the effect ending, however, there is a 20% chance to gain a stack of Tonic Affliction, which reduces ALL stats (health, armor, damage, speed, etc.) by 5% while the player is not under the effects of the Tonic. The debuff comes in the form of a grayed out, special type of item, similar to a consumed Dio's Best Friend. Tonic Affliction stacks, giving an additional -5% to every stat each stack.
Refreshing the Tonic before the end of the duration will not roll debuff stacks for each use, only one roll each time the buff wears off. Any combination of cooldown reducing items that allows for 100% uptime of the Tonic buff prevents the player from ever incurring debuff stacks - this would require the player to achieve a cooldown reduction of at least 66% to prevent downtime.
The Spinel Tonic is unlocked through the "Cosmic Explorer" challenge (Discover and enter three unique portals.)