Xylazine is a pharmaceutical drug used for sedation, anesthesia, muscle relaxation, and analgesia in animals such as horses, cattle, and other non-human mammals. Veterinarians also use xylazine as an emetic, especially in cats. It is an analog of clonidine and an agonist at the α₂ class of adrenergic receptor.

This is more and more frequently being added to your “boy” to increase the effects of opioids like fentanyl. However because it’s a sedative Narcan won’t work on it. There’s also a lot of reports of it causing increased ulcerations and wounds, although at this point that’s mostly anecdotal.

Here's a recent article about xylazine.




Diphenhydramine, a common over-the-counter antihistamine, has been combined with opioids as an adulterant in illicit drug supply, and can be used to reduce opioid-related side effects such as itchy skin because of histamine release from opioid use.



Quinine is a medication used to treat malaria and babesiosis. This includes the treatment of malaria due to Plasmodium falciparum that is resistant to chloroquinewhen artesunate is not available. While sometimes used for nocturnal leg cramps, quinine is not recommended for this purpose due to the risk of serious side effects. Quinine is also used as an ingredient in tonic water to impart a bitter taste.

Quinine has been reported as an adulterant in the illicit drug supply, including heroin, fentanyl, methamphetamine and cocaine, for many decades. It is generally added to increase total drug volume for distribution and to dilute the drug being cut.



Lidocaine is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lidocaine typically begins working within several minutes and lasts for half an hour to three hours.Lidocaine mixtures may also be applied directly to the skin or mucous membranes to numb the area. It is often used mixed with a small amount of adrenaline (epinephrine) to prolong its local effects and to decrease bleeding.



Quetiapine, sold under the brand name Seroquel among others, is an atypical antipsychotic medication used for the treatment of schizophrenia, bipolar disorder, and major depressive disorder. It is also used off label as a sleep aid due to its sedating effect.



Caffeine is a central nervous system stimulant of the methylxanthine class. It is used as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine to the adenosine A1 receptor, which enhances release of the neurotransmitter acetylcholine.

The addition of caffeine to heroin may be to allow it to vaporize at lower temperature thus giving a faster rush when smoked, and to counterbalance the sedative effects.



Acetaminophen (Paracetamol) is a medication used to treat fever and mild to moderate pain. Common brand names include Tylenol and Panadol.

Acetaminophen may be added because of its analgesic properties and its bitter taste which can disguise poor quality heroin.