Lean does produce real psychoactive effects. The combination of codeine and promethazine in prescription cough syrup creates a sedative, euphoric high that slows the central nervous system. But the drug works through mechanisms that make it genuinely dangerous, especially at the doses people typically consume recreationally.
What Lean Actually Contains
Lean starts with prescription cough syrup containing two active ingredients: codeine and promethazine. A standard formulation contains 10 mg of codeine and 6.25 mg of promethazine per teaspoon, plus about 7% alcohol. Users mix this syrup into soda or other sweet drinks, often adding hard candy for flavor. The mixture goes by several names: purple drank, sizzurp, dirty sprite.
Both ingredients are doing real pharmacological work. Codeine is an opioid that gets converted into morphine inside your body. It binds to the same receptors that heroin and prescription painkillers target. Promethazine is an antihistamine with strong sedative properties. It amplifies the drowsy, relaxed feeling codeine produces. Together, they create a compounding depressant effect that neither drug would produce alone.
What the High Feels Like
People use lean for its sedative euphoria. The codeine component produces a warm, relaxed feeling as it converts to morphine and activates opioid receptors in the brain. Promethazine deepens the sedation and can reduce nausea that opioids sometimes cause, making the experience feel smoother. Users commonly report heavy drowsiness, a sense of calm, and slowed perception of time.
The effects aren’t all pleasant. Drowsiness can tip into confusion. Some users experience hallucinations. The high sugar content from the soda and candy masks the drug’s potency, which makes it easy to drink far more than intended. Because lean is sipped slowly rather than taken as a measured dose, people often lose track of how much codeine they’ve actually consumed over the course of an evening.
Why the Combination Is Especially Risky
The core danger of lean is respiratory depression, which means your breathing slows down. Codeine does this on its own as an opioid. Promethazine does it too, through a separate mechanism. When you combine them, the effect on breathing isn’t just additive. It’s synergistic. Each drug amplifies the other’s ability to suppress the brain’s drive to breathe.
At recreational doses, breathing can slow to four to six breaths per minute. For reference, a normal resting rate is 12 to 20 breaths per minute. This is how lean kills people. The classic signs of opioid overdose are pinpoint pupils, severely slowed breathing, and loss of consciousness. In an overdose, breathing can stop entirely.
The risk climbs further when people add other substances. Survey data from lean users found that some mix in additional opioids, alcohol, or benzodiazepines. Every one of these combinations increases the chance of fatal respiratory failure.
Tolerance and Dependence Build Quickly
Because codeine converts to morphine, regular lean use creates the same dependence cycle as other opioids. Your brain adjusts to the presence of the drug, requiring more to achieve the same effect. What started as a few ounces of syrup per session gradually becomes much more, and the line between a recreational dose and a dangerous one gets thinner.
Stopping after regular use triggers opioid withdrawal. Symptoms typically start 8 to 24 hours after the last dose and include nausea, vomiting, diarrhea, muscle cramps, anxiety, insomnia, sweating, and watery eyes and nose. The acute phase lasts 4 to 10 days. After that, a protracted withdrawal period can stretch up to six months, marked by persistent cravings and a general sense of feeling unwell.
Long-Term Health Effects
Chronic opioid use, even through oral consumption, damages the body in ways that accumulate over time. Persistent constipation is nearly universal among regular users. Lung problems become more likely because opioids continuously suppress normal respiratory function, leaving users more vulnerable to pneumonia and other infections. Hormonal disruption is common: men frequently develop sexual dysfunction, and women often experience irregular menstrual cycles. Depression and other mental health disorders occur at higher rates in chronic users.
The massive sugar intake from the soda and candy mixers adds its own toll. People who drink lean regularly are consuming enormous quantities of sugar in every session, which contributes to weight gain, dental decay, and metabolic problems over months and years.
Legal Status
Codeine-promethazine cough syrup is a controlled substance. Depending on the specific formulation and codeine concentration, it falls under Schedule III or Schedule V of the DEA’s drug scheduling system. Both classifications require a prescription. Possessing or selling the syrup without one is a federal offense. The relatively low scheduling compared to drugs like oxycodone or heroin reflects codeine’s lower potency per milligram, but it doesn’t mean the drug is safe, particularly at the volumes people consume recreationally.
Signs of Overdose
The three hallmark signs of opioid overdose are pinpoint pupils, dangerously slow or shallow breathing, and reduced consciousness ranging from extreme drowsiness to complete unresponsiveness. Seizures can also occur. If someone who has been drinking lean becomes difficult to wake, is breathing very slowly, or has blue-tinged lips or fingertips, that person needs emergency medical attention. Naloxone, available over the counter in most states, can reverse an opioid overdose and restore breathing if administered quickly enough.