Lean is a recreational drug made by mixing prescription cough syrup containing codeine and promethazine with soda, often a lemon-lime or grape flavor, and sometimes hard candy for extra sweetness. It goes by many names: purple drank, sizzurp, dirty Sprite, and others. People drink it for the slow, sedative high it produces. But lean carries serious risks that most users underestimate, including fatal respiratory depression, physical dependence, and overdose, even at amounts that might seem moderate.
What Lean Actually Contains
The active ingredient that drives the high is codeine, an opioid derived from the opium poppy. Each teaspoon of prescription cough syrup contains about 10 milligrams of codeine. The second active ingredient, promethazine, is an antihistamine that causes heavy sedation and amplifies codeine’s depressant effects. The syrup also contains about 7% alcohol. When mixed into a large cup of soda, the sweet taste masks the medicinal flavor and makes it easy to drink far more codeine than intended over the course of an evening.
Codeine is a Schedule III controlled substance at the dosages found in this syrup, meaning it has recognized potential for abuse and dependence. Obtaining it without a prescription is illegal. The prescription-only requirement exists specifically because of the risks that come with unsupervised use.
How It Affects Your Body
Codeine works by entering the liver, where an enzyme converts it into morphine. That morphine then binds to opioid receptors in the brain, producing pain relief, euphoria, and drowsiness. Promethazine layers on additional sedation, creating the slow, heavy, “leaning” feeling that gives the drink its name. Users typically describe feeling deeply relaxed, sleepy, and detached.
The sedation is not just pleasant relaxation. Promethazine impairs both physical and mental abilities, causing confusion and disorientation. It can also paradoxically trigger restlessness, agitation, or in rare cases seizures. Combined with codeine’s opioid effects, even a single session of drinking lean meaningfully slows your breathing, heart rate, and reflexes.
Why Some People Face Higher Risk
Your genetics play a surprisingly large role in how dangerous lean is for you personally. The liver enzyme that converts codeine into morphine varies dramatically from person to person. Roughly 1 in 13 people of European descent, and higher proportions in some other populations, are “ultrarapid metabolizers” who convert codeine to morphine much faster and more completely than average. For these individuals, even a standard dose of codeine can flood the body with morphine, causing extreme drowsiness, confusion, and dangerously shallow breathing. Some cases have been fatal.
On the other end of the spectrum, people with inactive copies of this enzyme get almost no morphine from codeine at all, which means they feel little effect and may drink larger quantities trying to get high, exposing themselves to promethazine toxicity and alcohol poisoning in the process. There is no way to know which category you fall into without genetic testing.
How Overdose Happens
The lethal oral dose of codeine in an adult is estimated at 0.5 to 1 gram. A standard bottle of prescription cough syrup can contain several hundred milligrams of codeine, so consuming a large portion of a bottle in one sitting puts users in a dangerous range. But the real problem is that lean contains two drugs that both suppress breathing. The FDA labels promethazine as capable of causing “potentially fatal respiratory depression” on its own, and notes that it is “additive to the depressant effects of codeine.” Each ingredient makes the other more dangerous.
Classic signs of a codeine overdose are a trio of symptoms: loss of consciousness, pinpoint pupils, and slow or shallow breathing. Skin turns cold and clammy, heart rate drops, and blood pressure falls. Adding alcohol or any other sedative (benzodiazepines, sleep medications, more alcohol in the soda mix) compounds these effects further. Many lean-related deaths involve this kind of stacking, where multiple depressants shut down the brain’s drive to breathe.
Long-Term Consequences of Regular Use
Because codeine is an opioid, regular use builds tolerance quickly. What produced a strong high initially stops working at the same dose, pushing users to drink more. Physical dependence follows. Chronic use of promethazine at high doses can cause severe impairment of cognitive and psychomotor function due to ongoing central nervous system depression. In extreme cases, promethazine toxicity has been fatal on its own.
Promethazine also blocks dopamine receptors in the brain, which creates a small but real risk of a condition called neuroleptic malignant syndrome, a potentially life-threatening reaction involving high fever, muscle rigidity, and altered consciousness. The overall incidence is low (estimates range from 0.02% to 3.23% among people using dopamine-blocking drugs), with a mortality rate around 5.6% when it does occur. Research suggests this reaction may depend more on individual susceptibility than on dose, meaning even relatively small amounts could trigger it in certain people.
The high sugar content of the soda and candy mixture, consumed regularly, also contributes to significant dental decay and weight gain over time.
Dependence and Withdrawal
Codeine dependence produces the same withdrawal syndrome as other opioids. Symptoms typically begin 8 to 24 hours after the last dose and can last 4 to 10 days. The experience includes nausea, vomiting, diarrhea, muscle cramps, anxiety, insomnia, hot and cold flushes, heavy sweating, and watery eyes and nose. It is intensely uncomfortable but rarely life-threatening on its own.
The psychological side of dependence is often harder to shake than the physical symptoms. Many people who use lean regularly describe relying on it to manage stress, anxiety, or sleep problems, which makes quitting difficult without addressing those underlying issues. The ritualistic nature of preparing the drink, choosing the soda, mixing it in a specific cup, sipping slowly, also creates strong behavioral habits that reinforce the cycle of use.