People abuse cough syrup because certain ingredients produce euphoria, hallucinations, or a sedative high when taken in large doses. The two main targets are dextromethorphan (DXM), found in many over-the-counter cold medicines, and codeine-promethazine prescription syrups. Both are cheap, easy to obtain relative to street drugs, and widely underestimated as substances of abuse.
Two Types of Cough Syrup, Two Different Highs
DXM and codeine work on completely different parts of the brain, which means the reasons people seek them out differ too.
DXM, the active ingredient in brands like Robitussin and Delsym, is a dissociative drug at high doses. Once your body metabolizes it, the resulting compound blocks a specific receptor involved in perception, memory, and consciousness. It works in a similar way to ketamine and PCP. At recreational doses, this produces feelings of detachment from your body, distorted sensory experiences, and hallucinations. The practice is sometimes called “robotripping.”
Codeine-promethazine syrup, often called “lean,” “sizzurp,” or “purple drank,” produces a very different experience. Codeine is an opioid that your body converts into morphine. It creates a warm, relaxed, euphoric feeling. Promethazine, the antihistamine paired with it, amplifies the sedation and adds to the drowsy, slowed-down state users are after. The mixture is typically poured into soda or mixed with candy to mask the taste. Some research has found that people use lean specifically to cope with PTSD and other mental health symptoms, essentially self-medicating with an opioid.
Why DXM Attracts Young People
DXM misuse is a particular concern among teenagers and young adults, largely because of access. It’s sold without a prescription in grocery stores and pharmacies. Several U.S. states, including Virginia, have passed laws requiring buyers to be at least 18 and show photo ID, but enforcement varies and many states have no age restriction at all. For a teenager curious about altered states of consciousness, cough medicine sitting in the family medicine cabinet represents zero cost and zero interaction with a drug dealer.
There’s also a perception that over-the-counter drugs are inherently safer than illicit ones. That perception is wrong, but it lowers the psychological barrier to trying it.
The DXM “Plateaus”
DXM users describe four distinct levels of intoxication, which they call plateaus. The effects escalate dramatically with dose, and the difference between a mild buzz and a medical emergency is not large.
- Plateau 1 (100 to 200 mg): Restlessness and mild euphoria, roughly comparable to a few drinks of alcohol. This is about 35 to 60 mL of syrup.
- Plateau 2 (200 to 500 mg): Exaggerated sounds and visuals, closed-eye hallucinations, and loss of balance. This requires drinking 60 to 185 mL of syrup.
- Plateau 3 (500 to 1,000 mg): Intense visual and auditory disturbances, altered consciousness, mania, panic attacks, and partial dissociation from reality.
- Plateau 4 (over 1,000 mg): Full hallucinations, delusions, complete dissociation, and loss of motor control. At this level, violent behavior, dangerously high body temperature, and death from cardiac or respiratory arrest become real possibilities.
The jump from “euphoria” to “complete psychosis” is one reason emergency rooms see so many DXM cases. Users who are chasing a plateau 1 or 2 experience can easily overshoot.
The Hidden Danger of Other Ingredients
One of the most serious risks of cough syrup abuse has nothing to do with DXM or codeine. Many cough and cold formulas contain acetaminophen (the active ingredient in Tylenol) as a fever reducer. Someone drinking large volumes of syrup to get high on DXM may unknowingly take a massive dose of acetaminophen along with it.
The FDA warns that liver damage can occur above 4,000 mg of acetaminophen in 24 hours. Acetaminophen overdose is responsible for more than half of overdose-related acute liver failure cases in the United States and roughly 20% of liver transplants. The liver damage typically peaks 72 to 96 hours after the overdose, meaning a person can feel fine for days before experiencing jaundice, organ failure, and potentially fatal complications. Many of these overdoses are unintentional, with nearly two-thirds occurring in people taking combination products (like opioid or DXM formulas that also contain acetaminophen).
Serotonin Syndrome Risk
DXM also boosts serotonin levels in the brain. For anyone taking an antidepressant, particularly SSRIs, this combination can trigger serotonin syndrome, a potentially life-threatening condition marked by agitation, rapid heart rate, high body temperature, muscle rigidity, and seizures. Case reports have documented serotonin syndrome from high-dose DXM combined with normal therapeutic doses of common antidepressants. Given how widely prescribed these medications are, especially among the young adults most likely to experiment with DXM, this interaction is an underappreciated danger.
Overdose Symptoms
A DXM overdose can cause slow or stopped breathing (particularly dangerous in children and adolescents), seizures, dangerously high or low blood pressure, and rapid or pounding heartbeat. Codeine overdose carries the classic opioid risks: severe respiratory depression, loss of consciousness, and death. The sedative effect of promethazine in lean compounds this breathing suppression.
Dependence and Withdrawal
Both types of cough syrup can produce physical dependence with regular use, though the withdrawal experiences differ.
Codeine withdrawal follows the typical opioid pattern: nausea, vomiting, diarrhea, muscle cramps, anxiety, insomnia, sweating, and hot and cold flushes. Symptoms generally begin within 8 to 24 hours after the last dose and last 4 to 10 days for short-acting opioids. After the acute phase passes, a protracted withdrawal period can stretch up to six months, characterized by a general sense of feeling unwell and intense cravings.
DXM dependence is less well-characterized clinically, but chronic users report tolerance (needing higher doses for the same effect), compulsive redosing, and difficulty stopping. The dissociative experience itself can become psychologically addictive, especially for people using it to escape emotional pain or mental health symptoms. Over time, heavy use has been associated with cognitive impairment and persistent psychotic symptoms that researchers have described as “the poor man’s psychosis.”