Adulterants in Drugs

Commonly Adulterated Drugs

Several illicitly obtained drugs are commonly found to be adulterated or otherwise contaminated with other substances. Examples include:1

  • Heroin.
  • Cocaine.
  • MDMA/Ecstasy.
  • Marijuana/Cannabis.
  • Counterfeit Prescription Drugs.

The Centers for Disease Control (CDC) estimates that, in 2017, 11.2% of people aged 12 or older had used illicit drugs in the past month.2 Although street drugs continue to be widely used throughout the U.S., the fact that these substances may be adulterated with a variety of chemicals or fillers—from bulking agents to crushed prescription medications to heavy metals—may not be common knowledge.

The term adulterant may be applied to a variety of substances used to increase the perceived quantity (i.e., used to increase the bulk or weight) of an illicit drug or to enhance the delivery of the drug in question; in addition to pharmacologically active adulterants, some samples of street drugs may be contaminated with manufacturing by-products such as glass and metals—including lead and aluminum.3

Commonly used bulking agents include cellulose, talc, as well as sugars such as dextrose, mannitol, lactose, and sucrose.1,3 In addition to these common players, other risky contaminants of different drugs can include infectious microorganisms like bacteria (e.g., Bacillus and Clostridium species) and certain types of fungi (e.g., Aspergillus).1,3

The Potential Harm of Adulterants in Illicit Drugs


In relatively recent years, heroin use has been on the rise; in 2016, nearly 950,000 people in the U.S. reported having used heroin in the previous year, a figure that continued a trend of increasing prevalence in use since 2007.4

Though there is a widespread perception that all heroin may be intentionally “cut” with adulterant substances at several points along its manufacturing and distribution timelines, in some instances its level of impurity may merely be a reflection of the presence of other opioid alkaloids, other manufacturing by-products, or degradation products rather than additive substances.1 On the other extreme, the amount of actual heroin a purported sample of the drug may end up being the smallest ingredient among up to 10 other adulterants.6 Whether or not the heroin present in a given sample is this overwhelmingly outnumbered, any adulterants present may presumably be added for a variety of reasons—such as to more closely approximate the characteristic bitter taste of a purer product, to alter the drug’s pharmacologic effects, to lower the vaporization point of a product intended to be smoked, or simply to make it appear like there is more heroin or increase profits by diluting the primary active components.1,5

Some of the adulterants/contaminants that have been detected via different global forensic analyses include:1,2,5,6

  • Caffeine: Heroin is sometimes laced with caffeine since it may lower the vaporization point of the combination and, in doing so, increase the efficiency of drug delivery when smoked. While it has minimal impact on overdose risks, in large amounts, caffeine may contribute to anxiety and sleep disturbances.
  • Acetaminophen/Paracetamol: The bitter taste and mild analgesic effects of this substance (the active ingredient in many Tylenol products) may help to disguise poor quality heroin. Has a similar melting point to heroin, so the impact on various routes of delivery will be minimally impacted. Carries a risk of hepatotoxicity at high doses, especially in the context of concurrent alcohol use.
  • Griseofulvin: As with acetaminophen, the inherently bitter taste of griseofulvin may mask impure heroin.
  • Phenobarbital: A barbiturate that could compound the risks of respiratory depression—already a danger with heroin alone.
  • Quinine: This antimalarial substance has a bitter taste similar to heroin. It may also be used to enhance the respiratory “rush” associated with injected heroin. Quinine toxicity may be associated with gastrointestinal distress, hemolytic anemia, and cardiac conduction disturbances.
  • Fentanyl: The relatively recent inclusion of illicitly manufactured fentanyl into the supply of street heroin has further fueled an epidemic of opioid overdoses all over the US. Fentanyl is a much more potent respiratory depressing opioid than heroin; combining or substituting fentanyl for a drug thought to be heroin opioid drugs can drastically increase the risks of overdose and death.
  • Talc: Magnesium silicate is sometimes used as a filler in heroin preparations. Repeated injection use could increase the risk of talc related pulmonary fibrosis and other lung complications.


Though the purity of illicit cocaine samples in the U.S. may, on average, be relatively higher than some other countries, lacing or adulterating the product is still a common practice. Many cutting agents for cocaine resemble the white powdered form of the drug itself. In addition to sugars and starches, other adulterants frequently encountered in cocaine include:1,5

  • Lidocaine: Used in a variety of clinical settings, lidocaine has more powerful local anesthetic properties than cocaine itself. Its inclusion in illicit samples of cocaine could give users the impression of using higher quality cocaine. Lidocaine is also used as a dysrhythmic agent, and even small doses can result in adverse cardiovascular events. Other potential effects include nausea, vomiting, dizziness, tremors, and convulsions.
  • Levamisole: In 2009, DEA reports indicated that levamisole was a component of nearly 70% of seized samples of cocaine inbound for the United States. More recent reporting could bring that estimate to more than 80%. Levamisole is what’s known as an antihelminthic medication, and is used as a veterinary de-wormer. Aminorex, a metabolite of levamisole, has amphetamine-like stimulant effects. Given the white powdered form of levamisole and the long-acting psychostimulatory effects of its metabolite, it is theorized that levamisole may enhance and prolong the cocaine high in addition to bulking up the product for increased profits. This all comes at a cost to the cocaine user, though, as it levamisole a highly toxic substance and can result in fever, muscle aches, dizziness and, more seriously, pulmonary vasoconstriction, pulmonary hypertension, agranulocytosis, and necrotic skin lesions.
  • Phenacetin: This antipyretic/analgesic is banned in the U.S. due to its association with kidney failure and potential carcinogenicity, but it may still show up in samples of illicit cocaine.
  • Diltiazem: This calcium channel blocking medication may actually provide some cardioprotective properties due to its vasodilatory effects. It is otherwise unclear why diltiazem regularly shows up as a cocaine cutting agent.


Despite any pretense of purity used to market the substances, many amphetamine-derived “club drugs”—such as ecstasy, MDMA, or Molly—are encountered for illicit purchase as extremely impure combinations. Adulterants and contaminants that may be found in combination with these types of drugs include:1,8,9,10

  • Meth: Without the “entactogenic” effects of MDMA itself, methamphetamine as an adulterant may boost the psychostimulant effects expected from these types of drugs.
  • PMA/PMMA: Both para-methoxyamphetamine and para-methoxymethamphetamine are illicit stimulants sometimes detected in samples of ecstasy and MDMA or found to be entirely substituted for samples of drugs otherwise presumed to be MDMA-related. There is case report evidence of PMA/PMMA-related deaths.
  • Dextromethorphan (DXM): This ingredient is found legally in cough suppressants, but when taken in high doses, its dissociative/euphoric effects may elicit a subjective high similar to that of MDMA. High dose use may also result in lethargy, racing heart rate, ataxia, and increase the risk of heat stroke.
  • Ketamine: Another dissociative anesthetic that may show up regularly masquerading as or contaminating samples of MDMA.
  • Caffeine: Like heroin, caffeine is often found as an adulterant in MDMA and ecstasy. It is likely used simply as a bulking agent, but it could also contribute to the stimulant effects these drugs induce.
  • Butylone/Methylone: Among the novel psychoactive substances sometimes collectively referred to as ‘bath salts’, these synthetic cathinones have been detected in ecstasy users who otherwise report no knowledge of previous bath salt use.


Marijuana’s growing popularity over time has been accompanied with increasingly potent intoxicating forms of cannabis products, increased regulation at the state level, and a blurred distinction between medical and recreational use. However, marijuana continues to be purchased illegally, typically for recreational use, and such samples may be more likely to have adulterants or contaminants in them, including:1,11

  • Glass, aluminum, or lead: Presumably added to increase the weight or, in the case of aluminum, the result of an impure water supply used for growing the product. Respectively, these dangerous adulterants may increase the risk of sores or ulcerations in the mouth, pulmonary irritation, chronic cough, and lead poisoning.
  • PCP or formaldehyde: To alter the subjective effects of the drug, marijuana may be sold laced with additional psychoactive substances. However, such combinations may compound certain health risks, including the likelihood of unpleasant reactions such as hallucinations, panic, and anxiety.
  • Mold or fungus: As marijuana is a cultivated botanical product, some samples (including medical grade) may contain contaminating microorganisms—such as Aspergillus fungi—which, in some cases, may be associated with health issues such as pulmonary infections or fungal hypersensitivity reactions.

Counterfeit Prescription Drugs

People who engage in certain types of nonmedical substance use or misuse—including those who misuse opioids and/or benzodiazepines—may at some point encounter counterfeit forms of such drugs. Among the risks of consuming illicitly-obtained “prescription” medications is a lack of guaranteed product purity. In some reports, counterfeit versions of painkillers such as oxycodone or sedatives such as Xanax were found to contain fentanyl instead of the presumed drug. People who unsuspectingly consume fentanyl in this manner are placed at heightened risk of respiratory depression and overdose death.12

Get Help for Drug Addiction

Though much of the evidence regarding substance adulterants is anecdotal, some more detailed investigations have been conducted as toxicity and/or overdose trends have materialized over the years. In relatively recent years, increased painkiller and heroin overdoses due to fentanyl adulteration have drawn much more attention to the issue. And, while acute overdose deaths with adulterants like fentanyl may be the starkest of examples, there remain very real health risks associated with other potential contaminants such as certain filler products, diluents, active pharmaceuticals and, even, infectious agents such as fungus and bacteria.

Whether or not the presence of adulterants or contaminants is an issue, the compulsive use of drugs and alcohol is associated with significant challenges to health and wellbeing. Recovery can happen with the right help. Reach out for that help today.


  1. Cole, Claire & Jones, Lisa & Mcveigh, Jim & Kicman, Andrew & Syed, Qutub & Bellis, Mark. (2010). CUT: A Guide to Adulterants, Bulking Agents and Other Contaminants Found in Illicit Drugs.
  2. Centers for Disease Control and Prevention (CDC). (2017). Illicit Drug Use.
  3. Miller, S. C., Fiellin, D. A., Rosenthal, R. N., & Saitz, R. (2019). The ASAM Principles of Addiction Medicine, Sixth Edition. Philadelphia: Wolters Kluwer.
  4. National Institute on Drug Abuse. (2018). Heroin.
  5. Solomon, N., & Hayes, J. (2017). Levamisole: A High Performance Cutting AgentAcademic forensic pathology7(3), 469–476.
  6. National Institute on Drug Abuse. (2018). 2018 NIDA International Forum: Building International Collaborative Research on Drug Abuse, Plenary Sessions—Adulteration of Drugs With Toxic Cutting Agents: A Rapidly Developing Global Public Health Emergency.
  7. National Institute on Drug Abuse. (2018). What are the medical complications of chronic heroin use?
  8. Day, N., Criss, J., Griffiths, B., Gujral, S. K., John-Leader, F., Johnston, J., & Pit, S. (2018). Music festival attendees’ illicit drug use, knowledge and practices regarding drug content and purity: a cross-sectional surveyHarm reduction journal15(1), 1.
  9. Palamar, J. J., Salomone, A., Vincenti, M., & Cleland, C. M. (2016). Detection of “bath salts” and other novel psychoactive substances in hair samples of ecstasy/MDMA/”Molly” users. Drug and alcohol dependence, 161, 200–205.
  10. United States Department of Justice—Drug Enforcement Administration. (2018). Drugs of Abuse.
  11. National Drug Intelligence Center. (n.d.). Fry Fast Facts. 
  12. Drug Enforcement Administration. (2016). Counterfeit Prescription Pills Containing Fentanyls: A Global Threat.
  13. Vestal, C. (2018). These Pills Could Be The Next U.S. Drug Epidemic. The Pew Charitable Trusts.
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