Lets make some "dirty" potions.

[Tetrasodium]

Everyone knows the standard potions in the PHB for the various spell. Those clean & reputable potions are great and all, but they are too easy & the potion mixing side effect thing is too much effort. From time to time the various d&d books hsve mentioned various illicit drugs that may or may not be of maggical sourcing; but I wanted some other fun options that players might actually want to take. In a period of insomnia, I came up with a few & was wondering what you guys might be inspired to add


Troll's Blood: This common street potion does not actually contain any part of a troll, in fact some say it's a few too many shortcuts shy of a bulls strength potion. The foul smelling brew typically has a consistency similar to that of honey. Imbibing this potion of questionable legality grants advantage on strength checks & death saves for 1 hour. After the hour has passed, the user suffers 1d4 constitution damage. Lost points of constitution can be recovered with a greater restoration spell as normal. In addition, any attac, save, or ability check resulting in a natural 20 will recover 1 lost point.

Gryphon's wings: Another dirty potion not containing any substance derived from it's namesake. Often taken by young apprentices hoping to squeeze in a few hours of extra study instead of sleeping. Drinking this sweet smelling brew grants benefits of a long rest in the time normally needed for a short rest, but any saving throws are made at disadvantage until the next long rest. After the short rest is completed roll a d20, on a roll of 9-20 there are no futher side effects; however a roll of 1-8 will result in the die used for saving throws to drop one step each time (d20>d12>d10>d8>d6>d4). This effect can be rolled back 1 step with a lesser restoration followed by a long rest. The smell is indeed sweet, but the taste is often compared to rotten carrion.

Iron Golem's Might: This Iridescent liquid grants the drinker something approaching resistance to bludgeoning, piercing, & slashing damage for one minute, but can continue for up to five minutes provided the user takes at least 1 point of damage each round. The damage reduntion must be tracked for the duration as the drinker will suffer all of that damage in a single lump after the effect ends. This damage cannot be further reduced as it is simply the mind catching up to what may very well be beyond fatal damage. Rules for death by massive damage can be found on page 197 of the PHB.

Harpy's voice: Similar to Troll's Blood short cut of a potion, this grants advantage on charisma checks & saves against charm until the next long rest, but any roll of a 1 on a d20 between imbibing this & taking that rest results in a loss of voice until the drinker recieves both lesser restoration spell & completes a long rest.

[D-naras]

I'm game.

• Cat's Eye Philter: This iridescent fluid (which might contain cat pieces based on its quality) grants the imbiber 10 temporary hit points, Darkvision, advantage on Dexterity ability checks and they ignore all Exhaustion effects for 1 hour. At the end of the duration, the imbiber must make a Constitution saving throw at a DC of 10. On a success, they gain 1 level of Exhaustion. On a failure, they gain 1d4 levels of Exhaustion.
• Size Regulator: This viscous gray fluid turns anyone that drinks it to Medium size for 1 hour. If the user's original size was smaller, they drinker adds 1d4 to all their melee damage rolls and gains +5 ft speed. If they were larger, they have a penalty of 1d4 to all their melee damage rolls and their speed is reduced by 5 ft. The regulator can also be used as a poison on a weapon that deals slashing or piercing damage. In that case, the victim is affected if they fail at a DC 12 Constitution save and the effects last for 1 minute.

[Thisguy_]

Have a few on me.


Milk of Potash: The imbiber ceases to taste for 30 minutes during & after drinking, after which point they will universally report the distant aftertaste of having licked a piece of coal. Those who consume it have advantage against poison for 30 minutes, but become poisoned for an hour afterwards. (I'm thinking 5e's condition poison for the aftereffect, but any poison for the main effect.)

Feast's shadow: Inside of the bottle, the image of a delicious meal may be seen. Despite its looks, the substance in the bottle is a drinkable liquid which fills one's stomach when drunk as though they had partaken of a proportionate amount of the depicted meal. They will taste every moment, every flavor, every texture, and will feel filled by it appropriately, but it is of absolutely no nutritional value and over-consumption will quickly (worse, in fact, than simply not eating) lead to malnutrition.

Eyeblood Potion: This sufficiently gross-sounding brew is primarily poison. However, it has hallucinogenic properties which frequently give the imbiber insight into the past, present, or future which they did not have before. Events of direct interest to them are the most likely things that they will see. However, while experiencing these, they will be completely incapacitated, and afterwards, they will experience all of the more usual effects of drinking poison, which, as a reminder, they did.

[RSZealot]

Wire-And-Steel Extract
For three hours after this potion is imbibed, you may choose to gain advantage on any Wisdom or Intelligence roll. If you do, you immediately take 2d6 psychic damage as immense knowledge assaults your mind.
If at any point during the potion's effect the result of any Intelligence or Wisdom roll is a natural 1, you take 2d6+2 psychic damage and is paralyzed for one minute.


This is something I've used in a homebrew campaign, redone for DnD. On that same note:


Snakebite Brew
Upon imbibing this potion, you must make a DC 14 Constitution saving throw. On a success, regain hit points equal to 2d4+ your total levels. On a failure, take poison damage equal to 1d4+ your total levels.

[Spore]

Demon Dream:
Made of extremely diluted Quasit blood this potion takes on a dark red tone that swirls in its flask even if completely motionless.

With this concoction you invite the Fury of the Abyss to fill your very being. Similar to the Barbarian's Rage class feature you can call upon all the strength your body can offer, without the usual side effect of exhaustion for 1d4 hours. You have advantage on Strength checks and gain resistance to any non magical non silvered bludgeoning, slashing or piercing weapon. Any 1st-3rd level spell you cast has all its variable maximized. This however cuts the effect of the potion short.

After the effect ends you suffer a random indefinite madness from the DMG. You never stated the debiliating effect should be reversable.

[Knaight]

Duelist's Draught: Drank before a particularly dangerous fight, Duelist's Draught gives Advantage to the first round of combat rolls. The second round is rolled as normal, and every subsequent combat roll is made with Disadvantage until a short rest is taken.

[Vaz]

Unfulfilled Desire; This potion appears to be a potion of indeterminate effect, and cannot be identified by taking a short rest. If the identify spell or similar is used, then only "It is unclear, although there is the feeling that Wish is involved with its creation at some point". When drunk, the effect lasts until dispelled, or the next time the drinker states "I wish", at which point the wish takes effect on the rest of the sentence available - with the exception that it is only an illusion.

[Jaxter Gronaldi]

Potion of Invincibility: the drinker will feel invincible. Attacks will not hurt not leave a mark. They do actually take damage, they just don't realize it. The potion lasts an indeterminate amount of time.

[Big Papa Turnip]

Couple of fake street drugs I made for an old homebrew campaign, I'm sure they can fit in here. If you use them, make sure the trustworthy businessman they purchase the potions from only tells them about the positive effects.

"Shilling"
A small vial full of bright silver liquid that resembles mercury.
Tastes like blood.
Gives you a silver tongue - literally and figuratively - for one hour.
For the duration, every time the imbiber makes a charisma check, flip a coin. On heads, they're especially persuasive and have advantage on the check. On tails, their tongue turns to solid silver for a few seconds and they have disadvantage on the check. After a few hours (or the next time the player OR character uses the restroom) the imbiber takes one damage and...passes a single silver coin.

"Two Ponies"
A murky, muddy-brown potion that feels much heavier than it looks.
Tastes like milled oats.
For one hour, the imbiber has advantage on strength checks and their carrying capacity is doubled. However, a few minutes after drinking, the user becomes convinced they are a horse. The character must run/walk on all fours whenever possible, cannot attack except via unarmed strike, and cannot speak or understand any language (Speak With Animals works, though).

"Hocus Pocus"
A curly, elaborate glass bottle that appears to be filled with shimmering, colorful starlight.
Tastes like a fruity alcoholic drink.
Hocus Pocus "grants the drinker great magical power". Have the player choose four cantrips and one 1st level spell from the Wizard spell list (Alternatively, have the DM choose, or just roll for them). The player can cast each of these spells once over the course of the next eight hours/long rest. They function as normal spells and use the player's primary class stat as the casting stat for saves and spell hit. Upon the final spell being cast, or upon the party ending their day or taking a long rest, the player who drank the potion takes one level of exhaustion per spell cast via this potion.
Be careful with this one, as it's the only one capable of killing a player outright.

[Primus Beno]

Pensat's Pensive Potion

The formula for this potion was created by an enchanter of ill repute, Pensat. Known for his cruelty, Pensat was able to distill someone's memory into a liquid form. The process was incredibly painful as the memory is ripped from the victim and liquefied. The memory is completely removed and the victim, who will remember the pain quite clearly of it's removal, will not remember the actual memory itself. The process occasionally will be used to remove a trauma from someone with the liquid being destroyed afterwords, but more often than not, it is used by rogue enchanters looking to market cheap thrill memories to the black market. Joy, love, sex, religious rapture, pain, torture all have buyers in the underworld. The potions have become quite popular with illithid as of late.

The Pensive Potion is a sluggish, muddy purple paste like that almost needs to be sucked out of the bottle. The memories will alter the flavor as it is drunk.

[JackPhoenix]

Not original, from 3.5e Eberron, but ported to 5e and used in the game.

Dreamlily extract
Milky, opalescent liquid that tastes like user's favorite drink when imbibed. Psionically active opiate imported from Sarlona used extensively by healers during the Last War. Strongly addictive. The user doesn't feel pain for 8 hours after consuming it, has an advantage on death saving throws, immunity to frightened condition and stays conscious and may act even on 0 hp. For the duration, the user can take either bonus action or action on his turn, but not both, and has a disadvantage on wisdom saving throws.
(Generally better for NPCs, who don't have so many uses for BA. The ability to shrug any hit with less damage than max hp when at 0 hp (at the cost of failed death save) leads to some hard to kill psychos)

[coolAlias]

Potion of Protection from Negative Energy
Gifted from a hag; upon imbibing, the user feels terribly cold but does become immune to negative energy effects such as the strength drain from Shadows. Astute observers (Wis [Perception] DC 15) will notice that the affected person no longer casts a shadow - until the Shadow created by this potion is destroyed, the affected person is resistant to healing effects and cannot be revived from death by any means short of a wish.

Potion of Enlarge
Another hag gift - works as normal but when the duration expires, the target becomes permanently affected by the reduce version of the spell until either dispel magic or remove curse is cast on them.

Other hag potions require various DC Con saves to avoid becoming poisoned for 1d4 hours, remain permanently in polymorphed (or other) form, etc.

[Sariel Vailo]

Oni blood brew
Gives advantage on strength and intimidation checks for 1 d10 hours.
This blue blood looking brew,with the viscosity of pitch the taste of iron and sweetness brings about a violent rage after its euphoric and perhaps strength related hallucinations. When you come down from the high you. Feel a burning rage inside you as if all of the hate you had ever felt comes rushing back.
1 gp
Per potion bottle of this brew.but user be warned tho not wholly illegal it is considered a enhancer.(performance enhancing drug meets testosterone pill) can eventually become a permanent effect including the rage. Character gains the flaw i am overly aggressive and easily insulted.

[ko_sct]

"Immortal's fortitude"
This foul potion smell of rot and death, actually drinking it involve a DC5 constitution check to avoid throwing up the potion immediately. For 5 min after drinking this potion, the imbiber do not fall unconscious after reaching 0 hp. Instead, upon reaching 0 hp, they can keep on acting normally and the DM will be the one tracking their hp. Upon reaching a negative amount of hp equal to their maximum amount of hp, the imbiber will be considered dead, but won't know it of be affected by his death until the potion stop being effective.



** So if a fighter with 100 max hp reach -100 hp on round 15, he wont die until round 50, at which point it is too late for revivify.

[Jama7301]

Cobra Concoction

This emerald green fluid moves with an oily consistency within it's vial. Once consumed, until your next short or long rest, you may regurgitate the potion in a venomous spray in a 15' cone. All creatures in the cone must succeed on a DC 14 Constitution save, or take 10 Poison damage from inhaling the potion, and suffer disadvantage on all attack rolls and skill checks until the end of their next turn. A successful save reduces the damage by half, and does not grant Disadvantage.

After releasing the potion, you must succeed on a DC 16 Constitution saving throw, or suffer 1d4 Constitution damage until the end of your next long rest. On a successful save, take 5 Poison damage.

[Samayu]

Wire-And-Steel Extract

Snakebite Brew
Upon imbibing this potion, you must make a DC 14 Constitution saving throw. On a success, regain hit points equal to 2d4+ your total levels. On a failure, take poison damage equal to 1d4+ your total levels.
Sounds like something a barbarian would bring from his home tribe.

[NinaWu]

Thanks for all the unique potions. A great way to bring variety and uncertainty to any campaign!

[PhantomSoul]

Troll's Blood: This common street potion does not actually contain any part of a troll, in fact some say it's a few too many shortcuts shy of a bulls strength potion. The foul smelling brew typically has a consistency similar to that of honey. Imbibing this potion of questionable legality grants advantage on strength checks & death saves for 1 hour. After the hour has passed, the user suffers 1d4 constitution damage. Lost points of constitution can be recovered with a greater restoration spell as normal. In addition, any attac, save, or ability check resulting in a natural 20 will recover 1 lost point.


Alternatively: This common poison does not actually contain any part of a troll, in fact some say it's a few too many shortcuts shy of a Potion of Intellect.* The foul-smelling brew somehow has a consistency similar to that of honeycomb, without being solid. Imbibing this potion of questionable appeal grants disadvantage on any ability checks and saving throws that use Charisma, Intelligence or Wisdom for 1 hour, but you gain 1d4 Constitution for the duration and gain immunity to Psychic damage. You will immediately respond by yelling whenever someone speaks to you or you try to correct someone for the duration of the potion's main effects. Additionally, roll a Wisdom saving throw with a DC of 15 when the potion's main effects wear off, still at disadvantage (but applying any applicable bonuses from your ability modifiers and your proficiency bonus). If you fail the saving throw, you respond by yelling at any time someone refers to events that happened during the hour that followed imbibing the potion, and you assume any stance or position that you took while under the potion's effects.



__________
* I don't know of any existing potion to boost or flaunt intelligence, so I'm going with this.**
** Yes, this reply has footnotes.