Lean is a recreational drug mixture that slows down your central nervous system, producing feelings of euphoria, heavy sedation, and a dreamlike state. It’s made by mixing prescription cough syrup containing codeine (an opioid) and promethazine (a sedating antihistamine) with soda and sometimes hard candy for flavor. The combination creates a synergistic depressant effect that goes well beyond what either ingredient would produce alone.
What’s Actually in It
The active ingredients in lean are codeine and promethazine, both found in certain prescription cough syrups. Codeine is an opioid, the same class of drug as morphine and heroin, though weaker on a dose-for-dose basis. Your liver converts codeine into morphine, which then binds to opioid receptors in your brain to block pain signals and trigger a release of feel-good chemicals.
Promethazine is an antihistamine with strong sedating properties. On its own, it causes drowsiness and reduces nausea. But when paired with codeine, it amplifies the sedation and euphoria while also preventing the nausea that opioids commonly cause. This means people can drink more of the mixture without feeling sick, which makes it easier to accidentally consume dangerous amounts.
The soda and candy aren’t just for taste. The sugar masks the bitter medicinal flavor of the syrup, and the carbonation makes it easy to sip slowly over hours, often from a double-stacked styrofoam cup (which is where the drink gets some of its other names, like “purple drank” or “sizzurp”).
How It Feels
Lean produces a slow, heavy euphoria that users describe as a warm, relaxed, almost floating sensation. Because both active ingredients are central nervous system depressants, the overall experience is one of extreme sedation. Your thinking slows, your body feels heavy, and your reaction time drops significantly. Some users report mild hallucinations or a dissociative, dreamlike state where they feel disconnected from their surroundings.
The high typically sets in within 30 to 45 minutes and can last several hours, depending on how much is consumed. Drowsiness is the most consistent effect. Other common short-term effects include dizziness, blurred vision, constipation, nausea (especially at higher doses), and impaired coordination.
The Serious Physical Risks
The most dangerous thing lean does is slow your breathing. Codeine, like all opioids, suppresses the brain’s respiratory drive. At high enough doses, breathing becomes shallow and labored, or stops entirely. This is the primary way lean kills people. Promethazine compounds this risk by adding its own sedative load on top of the opioid effect.
Other acute risks include:
- Dangerously low blood pressure and a weak pulse
- Seizures, particularly from promethazine at high doses
- Heart rhythm problems, since both codeine and promethazine can affect cardiac function
- Loss of consciousness that can progress to coma
Because lean is sipped casually over long periods, often at social gatherings, it’s easy to lose track of how much codeine you’ve actually consumed. There’s no standardized “dose” when you’re pouring cough syrup into a cup of soda, and individual sensitivity to opioids varies enormously. Some people metabolize codeine into morphine much faster than others due to genetic differences, which means the same amount can be mildly sedating for one person and life-threatening for another.
What Happens With Regular Use
Codeine is addictive in the same way all opioids are addictive. With repeated use, your brain adjusts to the constant presence of the drug by reducing its own production of natural feel-good chemicals. This means you need more lean to get the same effect (tolerance), and you feel worse than your baseline when you stop (dependence).
Chronic use takes a toll on multiple organ systems. The liver, which has to process both the codeine and the large amounts of sugar and other syrup ingredients, can develop inflammation over time. Persistent constipation from opioid use can become severe enough to cause bowel obstruction. The promethazine component, used long-term, has been linked to neurological symptoms including involuntary muscle movements.
Cognitive effects are also well documented. Long-term opioid use disrupts the brain’s communication pathways, affecting mood regulation, decision-making, and memory. Users often describe a persistent mental fog that lingers even between doses.
Withdrawal and Dependence
Codeine is a short-acting opioid, so withdrawal symptoms typically begin 8 to 24 hours after the last dose and last 4 to 10 days. The acute phase includes nausea, vomiting, diarrhea, muscle cramps, anxiety, insomnia, sweating, and hot and cold flushes. It’s intensely uncomfortable but rarely life-threatening on its own.
What many people don’t expect is the protracted withdrawal phase that follows. After the acute physical symptoms pass, a period of general malaise, low mood, and strong cravings can persist for up to six months. This extended phase is a major reason relapse rates are high. The cravings aren’t just psychological; your brain’s reward system has been physically reorganized around the drug, and it takes months to recalibrate.
Why Mixing With Other Substances Is Especially Deadly
Lean is frequently consumed alongside alcohol, marijuana, or anti-anxiety medications like benzodiazepines. Combining lean with any of these dramatically increases the risk of fatal respiratory depression. The FDA has issued its strongest possible warning about combining opioids with benzodiazepines or alcohol, noting that the combination can cause extreme sleepiness, slowed or stopped breathing, coma, and death.
One analysis of emergency department data found that alcohol was involved in roughly 18.5% of opioid abuse-related ER visits and 22% of opioid-related deaths. Because lean is often used in party settings where alcohol is present, the real-world risk is higher than many users realize. Even a moderate amount of alcohol on top of lean can push someone’s breathing below the threshold needed to survive.
Signs of an Overdose
Knowing what a lean overdose looks like can be the difference between life and death for someone nearby. The warning signs include extremely slow or shallow breathing, blue-tinged fingernails or lips, cold and clammy skin, pinpoint pupils, confusion, loss of consciousness, and a weak pulse. Muscle twitching and stomach spasms can also occur.
If someone shows these signs, they need emergency medical help immediately. Naloxone, a medication that rapidly reverses opioid effects, can restore breathing within minutes and is available without a prescription in most states. It won’t cause harm if the person turns out not to have an opioid overdose, so there’s no reason to hesitate using it.