Lean, also called purple drank or sizzurp, is a mix of prescription cough syrup containing codeine and promethazine, a soft drink, and often hard candy for flavor. It damages your body in multiple ways: codeine is an opioid that depresses breathing and builds dependence quickly, promethazine amplifies sedation while lowering your seizure threshold, and the massive sugar load erodes your teeth and contributes to weight gain. The combination is more dangerous than most people realize, with a fatal dose of codeine starting as low as 500 milligrams, an amount that’s surprisingly easy to reach when sipping from a styrofoam cup all night.
What Lean Does to Your Body Right Away
The immediate effects of lean come from two drugs working together. Codeine is converted into morphine in your liver, producing a slow, heavy euphoria. Promethazine is an antihistamine that causes deep drowsiness on its own and intensifies the opioid high. Together, they create the signature “leaning” sensation: extreme sedation, slowed reflexes, and a foggy mental state.
Even a single use carries real risks. The most dangerous short-term effect is respiratory depression, where your breathing slows to a rate that can starve your brain and organs of oxygen. Other acute effects include hallucinations, impaired coordination, nausea, and neurological complications. Because lean is sipped gradually rather than taken in a measured dose, it’s easy to consume far more codeine than intended before the full effects hit. People sometimes fall asleep and stop breathing altogether.
Why Some People Are at Higher Risk
Your body processes codeine using a specific liver enzyme that converts it into morphine. About 5 to 10 percent of people are “ultrarapid metabolizers,” meaning their bodies convert codeine into morphine much faster and in larger amounts than normal. For these individuals, even a standard therapeutic dose can cause life-threatening respiratory depression. The FDA has flagged this on codeine’s drug label as a potentially fatal risk. Most people who drink lean have no idea whether they carry this genetic trait, which makes every use a gamble.
Promethazine adds its own layer of danger by lowering the seizure threshold. If you have any predisposition to seizures, or if you’re combining lean with other substances that affect the brain, promethazine makes a seizure more likely. This risk compounds with higher doses.
Organ Damage From Regular Use
Repeated opioid use takes a toll on the kidneys. Codeine can cause acute kidney injury through several mechanisms: dehydration from nausea and reduced fluid intake, dangerously low blood pressure, and a condition called rhabdomyolysis where muscle tissue breaks down and clogs the kidneys. Repeated episodes of acute kidney injury can progress to chronic kidney disease, meaning permanent loss of kidney function that doesn’t reverse when you stop using.
The liver faces its own burden. It’s responsible for converting codeine into morphine, and chronic use forces it to work overtime processing both codeine and the acetaminophen sometimes found in certain cough syrup formulations. Over months or years, this can contribute to liver inflammation and damage. The combination of organ stress, poor nutrition (common among heavy users), and chronic dehydration accelerates the decline.
Tooth Decay and Metabolic Harm
Lean is typically mixed with a sugary soda and dissolved hard candy, creating an extremely high-sugar drink that users sip continuously over hours. This prolonged sugar exposure feeds acid-producing bacteria in the mouth, which attack tooth enamel and cause cavities and decay. Dentists who treat lean users often see severe, widespread damage that progresses faster than typical soda-related decay because of how long the drink sits against the teeth.
The sugar load also contributes to weight gain, insulin resistance, and a higher risk of developing type 2 diabetes and heart disease over time. A single serving of lean can contain more sugar than several cans of soda, and heavy users may drink it daily.
How Dependence Develops
Codeine is an opioid, and your body builds tolerance to it just like it does to heroin or prescription painkillers. What starts as occasional sipping can shift into daily use within weeks. As tolerance grows, you need more to feel the same effect, which pushes you closer to the overdose threshold every time you increase your dose.
Withdrawal from codeine typically begins 8 to 24 hours after the last dose and lasts 4 to 10 days. Symptoms include nausea, vomiting, diarrhea, muscle cramps, anxiety, insomnia, hot and cold flushes, heavy sweating, and watery eyes and nose. These symptoms are intensely uncomfortable but rarely life-threatening on their own. What makes opioid withdrawal particularly difficult is the protracted phase that follows: up to six months of reduced well-being, low energy, and strong cravings that make relapse common without support.
The psychological pull is strong partly because lean is deeply embedded in certain music cultures, which normalizes its use and makes it feel less like “real” drug use. But the pharmacology is identical to other opioid addictions. Your brain adapts to the presence of the drug, and stopping feels physically and emotionally devastating.
The Overdose Threshold Is Lower Than You Think
Codeine has what pharmacologists call a narrow therapeutic index, meaning the gap between a dose that gets you high and a dose that kills you is small. Fatal overdoses have occurred at doses as low as 500 to 1,000 milligrams. Prescription cough syrup typically contains 10 milligrams of codeine per 5 milliliters, so a full bottle can contain several hundred milligrams. Pouring generously into a large cup, refilling throughout the night, or sharing from a communal bottle makes it easy to cross into dangerous territory without tracking how much you’ve consumed.
The risk multiplies dramatically when lean is combined with alcohol. Both alcohol and codeine suppress breathing, and drinking them together can make it hard to breathe at doses that would be survivable with either substance alone. The CDC warns that using alcohol alongside opioids can damage the brain and other organs and lead to death. Mixing lean with benzodiazepines (anti-anxiety medications like Xanax) carries the same compounded risk.
Legal Restrictions on Codeine
Codeine-promethazine cough syrup is a Schedule V controlled substance in the United States, meaning it requires a prescription in most states. The FDA has added its strongest warning, a contraindication, stating that codeine should not be used to treat pain or cough in children under 12. Single-ingredient codeine products and all codeine cough syrups are approved only for adults. Some states still allow over-the-counter codeine products with pharmacist approval, and the FDA has indicated it is considering additional restrictions on those.
Despite these controls, lean remains widely available through prescription fraud, theft, and a robust black market where bottles of codeine-promethazine syrup sell for hundreds of dollars. The high street price hasn’t reduced demand so much as it has created a secondary market for counterfeit syrups, which sometimes contain fentanyl or other synthetic opioids and carry an even higher overdose risk.