Lean is a pattern of use, not a single drug. The risk profile of any given Lean preparation depends entirely on which ingredients are present, in what quantity, and what else the person has consumed.
In its classic US description, Lean (Purple Drank, Sizzurp) combines a codeine-containing cough syrup with a sedating antihistamine, most commonly promethazine, and is dissolved into a carbonated soft drink, often with added sugar and ice. The result is a sweetened, coloured drink consumed in unmeasured quantities, sometimes from a double-foam cup, a style associated with hip-hop culture and used to keep the drink cold longer. It may be used socially or alone.
UK Lean differs from the US version in important ways. Access routes differ: in the UK, cough medicines containing promethazine (as Phenergan Elixir) and dextromethorphan (DXM), such as Covonia, are more readily available than prescription codeine syrups. UK Lean preparations, therefore, frequently involve DXM-dominant or antihistamine-dominant ingredient profiles rather than pure codeine-promethazine combinations. Variable ingredient combinations produce different effects and harms, a fundamental reason why practitioners must understand all potential ingredients, not just codeine.
A key risk factor is the perception of medicinal products as ‘low-risk’ among young people. The availability of Lean ingredients at pharmacies or general sales list (GSL) outlets creates a false sense of safety. The perception that ‘it’s just medicine’ significantly delays recognition of dependence and reduces individuals seeking help.