Heroin comes in a variety of forms, but it can broadly be split into three groups: black, brown, and white.
Black heroin is the least pure on average, and white is the purest. Heroin is regularly cut with substances called adulterants to make selling heroin more profitable or a dealer’s product more desirable. Some of these added ingredients can increase the risks and dangers of heroin, which is an already dangerous substance.
Different Types of Heroin
Broadly, heroin comes in three forms, although it should be noted these forms exist on a spectrum with not all available heroin neatly falling into one of these three groups. These are the major forms of heroin:
Black (Black Tar Heroin)
Black tar heroin is a form of heroin that dominantly comes from Mexico. Unlike most other heroin forms, it comes in a gooey, solid form (hence its name). It tends to have significantly lower purity than many other forms of heroin, with purity generally considered to plateau around 25% to 30%.
While all forms of heroin are dangerous, black tar heroin is often impure or cut with other substances that make it particularly risky.
Brown heroin typically comes from Columbia, and it is in the form of a coarse powder. Compared to white heroin, it has poor water solubility and requires an acid to be added to change its solubility. It is considered to have good heat stability. Brown heroin is generally of “middling” purity. Black heroin is generally less pure, and white heroin is generally purer.
White heroin is what many imagine when they think of “pure” heroin, coming in the form of a white powder. It is highly dissolvable and acidic. This form of heroin generally comes from Southeast Asia.
While it’s true that white heroin tends to be the purest among heroin’s different forms, it is still very dangerous. Pure heroin is a potent opioid with significant addiction potential.
Common Cutting Agents
Heroin is frequently cut with substances called adulterants, which refers to substances added to a drug  This is generally done to either substitute some of an expensive substance with a cheaper substance, improving profits, or to change a drug’s properties so it is more desirable or addictive to consumers.
These cutting agents can often make a drug more dangerous, especially because customers do not always know what a substance has been cut with. Below are some common cutting agents or adulterants:
Caffeine is a stimulant. Cutting heroin, a depressant, with caffeine can possibly be an attempt to counteract the depressant properties of opioids and give the heroin a less “downer” high. Caffeine is also generally cheaper than heroin which can make it less expensive overall.
Paracetamol, also called acetaminophen, is one of the most common adulterants used to cut heroin. Crushed over-the-counter cold tablets can be used to cut black tar heroin, forming what is called cheese. The purity of heroin cut in this way is extremely low. Cheese contains on average about 2% heroin, 95% acetaminophen, and 4% to 5% of another over-the-counter drug, diphenhydramine HCL. This also makes this kind of heroin very cheap.
Heroin is also commonly just cut with other opioids, such as methorphan, morphine, or fentanyl. Because some opioids like fentanyl are even more potent than heroin, it can predispose the individual to accidental overdose.
Dangers of Cut Drugs
Cut heroin greatly increases the risk of serious complications and overdose.  While some individuals buy heroin cut with other substances intentionally to produce a certain chemical effect, most of the time this is not the case. Most of the time, customers are buying cut products unknowingly and ingesting unknown substances, which can lead to overdose or other complications. [5, 6]
If you are using illicit heroin, make sure you know what it is cut with. While this can be hard to ensure, some methods to prevent harm are to only buy from dealers that you know and trust, use chemical kits to test for the presence of common cutting agents (these are often called “test strips” and can be purchased at pharmacies or online), and use new doses of drugs in small amounts at first to ensure your body is tolerant before taking a usual or even high dose.
For more information about the risks of heroin use and to seek treatment for opioid use disorder, reach out to Bicycle Health.
Medically Reviewed By Elena Hill, MD, MPH
Elena Hill, MD; MPH received her MD and Masters of Public Health degrees at Tufts Medical School and completed her family medicine residency at Boston Medical Center. She is currently an attending physician at Bronxcare Health Systems in the Bronx, NY where ... Read More
- Heroin in Brown, Black and White: Structural Factors and Medical Consequences in the US Heroin Market. The International Journal of Drug Policy. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2704563/. May 2009. Accessed March 2023.
- Commentary – Heroin Purity and Adulteration: An Updated Snapshot From the Italian Early Warning System. European Review for Medical and Pharmacological Sciences. https://www.europeanreview.org/wp/wp-content/uploads/4461-4466.pdf. 2020. Accessed March 2023.
- Cutting the Cheese. Journal of Medical Toxicology. https://link.springer.com/content/pdf/10.1007/BF03160952.pdf. March 2008. Accessed March 2023.
- Serious Health Threats of Novel Adulterants of the Street Heroin: A Report From India During the COVID-19 Pandemic. BMJ Case Reports. https://harmreductionjournal.biomedcentral.com/articles/10.1186/s12954-021-00478-4. March 2021. Accessed March 2023.
- How Cutting Drugs Became Big Business. BBC News. https://www.bbc.com/news/magazine-11177126. September 2010. Accessed March 2023.
- Sold As Heroin: Perceptions and Use of an Evolving Drug in Baltimore, MD. Journal of Psychoactive Drugs. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6114137/. August 2018. Accessed March 2023.
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