Adulterants in Drugs

Most Commonly Adulterated Drugs

Some drugs are more commonly adulterated than others. These include:

  • Heroin
  • Cocaine
  • Ecstasy
  • Marijuana
  • LSD
  • Illicitly sold prescription drugs

The Centers for Disease Control (CDC) reports that, in 2014, 10.2 percent of people aged 12 and older had used illicit drugs in the past month. Although abuse of street drugs is a common problem in the US, the perception of many of these substances is that they are adulterated with a variety of chemicals or fillers, from crushed prescription drugs to dried herbs to glass.

The term adulterant applies to any substance in an illicit drug that is not the active ingredient. When measuring these substances, there are some indications of dangerous chemicals and added intoxicating substances; however, adulterants can also include nonreactive substances used to increase the bulk or weight of the drugs when sold. The most common of these bulking agents is sugar. These can be added intentionally, or they can be byproducts of the manufacturing process. In some cases, adulterants are bacteria, fungi, or other organisms that can cause infection.

Adulterants in Illicit Drugs and How They Cause Harm


Heroin is one of the most commonly abused street drugs. As a manufactured drug, some adulterants are a product of the process of converting opium plants into morphine, then into heroin. However, numerous other adulterants can be added to heroin to increase the drug’s potency, to make it appear like there is more heroin, or to allegedly take the “edge” off a heroin high. Some of these adulterants include:

  • Phenobarbital: This is a prescription barbiturate, which can enhance the psychoactive effects of smoking heroin. Because the effects of heroin are increased, however, overdose and death become more likely as a consequence of this combination.
  • Quinine: Used in tonic water and originally developed as an antimalarial medication, this substance enhances the respiratory “rush” of the first dose of heroin. However, this can also lead to depressed and stopped breathing, renal failure, gastric problems, visual disturbances including blindness, and overdose.
  • Cocaine: The combination of heroin and cocaine is referred to as a “speedball.” Although cocaine is a stimulant, it can enhance the intoxication from heroin and prevent the individual from feeling negative effects of heroin. Euphoria associated with cocaine can also cause the person to want more of the combination, which can rapidly lead to overdose.
  • Fentanyl: This recent combination has led to an epidemic of overdoses all over the US. Fentanyl is a powerful prescription opioid painkiller, so it is distantly related to heroin and more powerful than morphine. Combining opioid drugs can increase the risk of compounding negative side effects, including respiratory depression and coma. When heroin is laced with fentanyl, it becomes very likely that the person injecting this combination will experience an overdose.
  • Caffeine: Heroin is sometimes laced with caffeine to reduce the sleepiness or nodding effect that is associated with a pure heroin high. The caffeine also speeds up how rapidly heroin enters the bloodstream. While it does not contribute much to the risk of overdose, caffeine could trigger existing heart conditions and increase the produced sense of wellbeing enough that the user might take another dose too soon and overdose.
  • Bacteria and fungi: Heroin use is likely to spread infectious diseases, especially bacteria, which increase the risk of dangerous infections when injected into the veins.


In the US, cocaine is relatively pure compared to other countries. However, lacing or adulterating the product is still a common practice. Some common adulterants in cocaine include:

  • Lidocaine: Developed as a local anesthetic, lidocaine enhances the painkilling and numbing effects that cocaine already possesses and makes the person taking this combination feel like they are taking a higher grade of cocaine. However, smaller doses of this combination can lead to serious cardiovascular damage, nausea, dizziness, tremors, convulsions, and cognitive difficulties. Overdose also occurs more easily with this combination.
  • Levamisole: In 2005, the DEA found this adulterant in about 2 percent of cocaine the agency seized; by 2011, that had increased to 73 percent. This combination likely increases the amount of dopamine released into the brain, and levamisole has some reported amphetamine-like properties of stimulation. This could increase the amount of excitement felt by people who abuse cocaine, but it could also increase psychological and physical problems, such as paranoia, aggression, terror, tremors, heart problems, high blood pressure, and stroke.
  • Phenacetin: This analgesic is banned in several countries due to its suspected link to cancer, but it can still sometimes be found lacing cocaine. Phenacetin relieves pain in a similar way to cocaine, so it enhances the painlessness associated with cocaine highs. People who ingest this combination on a long-term basis are more likely to suffer bladder and kidney cancer, as well as other dangerous side effects from cocaine.


Ecstasy, MDMA, and related amphetamine “club drugs” tend to be extremely impure when sold on the black market. Other things the drugs may contain include:

  • MethMethamphetamine is related to other amphetamines, so inexpensive meth is often added to ecstasy, MDMA, or Molly to bulk up the intoxicant and to enhance the high. However, added meth can lead to serious heart problems and neurological side effects, including hallucinations, blackouts, amnesia, cognitive problems, and psychosis.
  • PMMA: Paramethoxymethamphetamine, or PMMA for short, is an illegal psychoactive chemical that is found regularly in ecstasy, MDMA, and related designer club drugs. High doses of this drug have led to death.
  • Dextromethorphan: This ingredient is found legally in cough suppressants, but when taken in high doses, it can lead to euphoric effects that mimic MDMA’s effects. When mixed with ecstasy or other amphetamines, this drug enhances euphoria but can also increase blood pressure, lead to tachycardia, and cause lethargy during the withdrawal period.
  • 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 enhance the excited euphoria these drugs induce.
  • Sugar: This adulterant does not react much with MDMA or ecstasy, and it is typically added as a bulking agent. However, those sensitive to sugar due to an underlying illness may experience negative side effects.


Marijuana’s popularity has led to higher grades of the substance, more regulation at the state level, and a differentiation in medical and recreational use. However, marijuana bought illegally, typically for recreational use, is more likely to have many adulterants in it, including:

  • Lead, aluminum, or glass: These might be added to increase the weight, or they might be byproducts of unclean or unsanitary conditions during processing. These dangerous adulterants can dramatically increase the risk of ulcers in the mouth and throat, lung damage, persistent coughing, and chemical poisoning, particularly lead poisoning.
  • PCP, cocaine, crack, and embalming fluid: On occasion, people struggling with polydrug abuse intentionally add other drugs to marijuana. However, sometimes marijuana is sold with these laced inside, allegedly to increase the high experienced by the person using marijuana. However, combining illicit intoxicants like these can cause negative side effects to compound, and the person could suffer from hallucinations, anxiety, paranoia, panic, rage, and the inability to distinguish reality from fantasy. Sometimes, large doses of these adulterants could lead to respiratory or heart failure, coma, overdose, and death.
  • Mold or fungus: Because marijuana is still grown illegally in poor conditions, the plants or surrounding environment can contain fungus spores or mold, which can contaminate the final product. This can lead to lung diseases like pneumonia or infections in the heart or blood vessels.


There are many news reports and urban legends of food being laced with LSD, including candy, gum, and even steaksLSD itself is a manufactured drug, and in recent years, it has reportedly been laced with PCP (phencyclidine). These two hallucinogens in combination can dramatically increase the psychological dangers associated with LSD, including paranoia, psychosis, terror, and aggression.

Impure Narcotic Painkillers

Oxycodone and hydrocodone are the primary culprits in the current opioid abuse epidemic. Most people who struggle with addiction to these substances are introduced through a doctor’s prescription but then are unable to stop taking these medications or take more to experience a high. If their doctor stops filling their prescription due to concerns about addictive behaviors, the individual may turn to illicit substances; sometimes, that means switching to heroin, but there is also an increasing black market for prescription narcotics.

Prescription painkillers on the black market are often laced with other substances. The most recent trend has been to lace Vicodin, Percocet, OxyContin, and other prescription pain relievers that are sold illegally with fentanyl, a pain medication more powerful than morphine. This rapidly increases the risk of overdose, respiratory depression, and death.

Get Help for Drug Addiction and Abuse

Most of the evidence regarding adulterants is anecdotal, although some studies have examined adulterants as they became more popular and led to waves of overdoses. Most recently, increased painkiller and heroin overdoses due to fentanyl have drawn more attention to the issue. Other adulterants, such as fungus, sugars, or lead, can cause serious health consequences, so the problem is widespread.

Use of illicit drugs carries many side effects that can severely damage health, so it is important to stop abusing illicit substances as soon as possible. Recovery can happen with the right help. Reach out for that help today.

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Editorial Staff
Editorial Staff, American Addiction Centers
The editorial staff of Greenhouse Treatment Center is comprised of addiction content experts from American Addiction Centers. Our editors and medical reviewers have over a decade of cumulative experience in medical content editing and have reviewed... Read More