Baldur’s Gate 3: What is Formula Gruna and should you drink it in BG3?

Formula Gruna is a mysterious and quite possibly nefarious elixir that can only be acquired in the third act of Baldur’s Gate 3.

The elixir grants a lasting effect that has the potential to be a massive buff or a bit of a nerf to your party depending on your composition, so it’s important you understand its effects before deciding to drink it. Even then, there’s a specific chain of events that must take place for this potion to exist, and those events start in the first half of Act Two.

This guide will detail the effects of Formula Gruna, what you need to do to make it available, and why you should or shouldn’t drink it.

What is Formula Gruna in BG3?

The name “Gruna” seems to be a placeholder for Gamma, meaning there existed a Formula A through Formula F—as much is stated by Araj Oblodra, the tasteful drow woman who created Formula Gruna. The formula is created from the blood of a True Soul, but not just any True Soul; the blood ingredient must come from the player character. This means you have to give Araj Oblodra your blood for the potion to be made, but I’ll cover all of that in detail in the next section.

Formula Gruna offers a devastatingly powerful permanent passive feature when consumed, Unstable Blood.

Unstable Blood is every bit as fun and chaotic as it sounds. This passive feature makes it so your blood is highly flammable and explodes when it comes into contact with fire. Thankfully, this doesn’t just mean you will die instantly if you’re exposed to fire. While the feature can certainly be dangerous, it’s more nuanced than that and can be leveraged as a powerful tool.

• Unstable Blood only applies to the blood that is outside your body.

This means you won’t combust and die when you’re hit with a Firebolt Cantrip, because you aren’t bleeding. It also means being in the radius of a Fireball won’t necessarily cause you to explode. In fact, this feature will almost never be triggered unless you have first taken melee damage.

Slashing, Piercing, and Bludgeoning damage all cause your character to bleed. This blood gets all over the ground around you, and as such it is the ground around you that becomes a flammable and explosive surface. If you’re still standing on top of your own blood when it goes boom, you take damage. If you were to Misty Step away from the enemy who just hit you and then shoot a Firebolt at them, only they will go boom, since only they are standing on your blood.

How to get Formula Gruna in BG3

Formula Gruna is offered by Araj Obloda in the Lower City of Baldur’s Gate, but she will only be there with the formula if you gave her your blood in Act Two.

Araj can first be encountered inside of Moonrise Towers, where she will beg you to force Astarion to drink her blood. Regardless of whether you do, she continues the conversation by asking for a sample of your blood, claiming she can brew a powerful elixir from it.

If you give Araj Oblodra a sample of your blood in Moonrise Towers, you will be given an elixir that offers one of many daily effects depending on the race of your character. More importantly, giving her your blood in Act Two means she can later be found in Act Three, where she will give you Formula Gruna. If you don’t give Araj your blood in Act Two, there’s no way to acquire Formula Gruna, since it will never be invented in that play-through.

Where to find Araj in Act Three

Giving Araj your blood in Moonrise Towers is only part of the equation; you can’t get Formula Gruna until you find her in the Lower City of Baldur’s Gate in Act Three.

Araj’s Act Three shop is located directly north of the Counting House and directly west of Sorcerous Sundries. When you first approach her shop, there will be a massive explosion, after which she will come running outside while trying to extinguish the flames from herself.

Speak to Araj, and the ensuing conversation will have entirely intuitive dialogue to obtain Formula Gruna. She will plainly offer the potion to you, and you will have clear cut “yes” or “no” responses.

Should you drink Formula Gruna in BG3?

In my opinion, you should drink the blood, however I’ll provide you with some pros, cons, and specifics so you can decide for yourself.

• Formula Gruna can and will hurt allies if they are standing near your blood when it ignites.
• The explosion caused when flame touches your blood can be halved or negated entirely by Fire Resistance.
• Any sort of passive burning auras will cause immediate combustion upon taking Slashing, Piercing, or Bludgeoning damage.

The character I first was offered Formula Gruna on just so happened to be a Draconic Bloodline Sorcerer with fire as my chosen element, so drinking the potion made a ton of sense. My character doesn’t take any fire damage, and has infinite ways to ignite her own blood as punishment to anyone that dares attack from up close.

Similarly, drinking Formula Gruna as Karlach is a great and devastating choice, as she will always be right up in enemies’ faces and barely takes any fire damage, so exploding every time she takes melee damage is way worse for foes than it is for her.

What you probably want to avoid is drinking Formula Gruna on a Cleric or other healer that is mostly going to be surrounded by allies instead of foes and who doesn’t have any reliable way of enduring or escaping the Unstable Blood firebomb.

Formula Gruna is devastating, and it’s up to you to channel that devastation in a way that hurts your enemies more than it harms you. If that sounds like something that interests you, then by all means drink the potion. If navigating a “blood goes boom” mini game doesn’t sound worth the extra power, you should probably pass this one up.