Lassi, a traditional North Indian drink, is known for its refreshing taste but can also cause drowsiness in some individuals. Dr. Viny Kantroo, a Pulmonology and Respiratory Medicine Specialist, explains that this drowsiness is often a natural physiological response, particularly due to the drink's dairy content and thickness. Lassi contains tryptophan, an amino acid that aids in the production of serotonin, a neurotransmitter that promotes relaxation. The drink's caloric richness, especially when sweetened, can also lead to a sluggish feeling after consumption. Ms. Ruchika Jain, Chief Dietitian at Fortis Hospital, adds that the presence of micronutrients like zinc and magnesium in curd can further enhance its sleep-promoting effects. While not everyone feels sleepy after drinking lassi, factors such as quantity consumed, sugar content, and individual metabolism can influence the response. Experts recommend moderation and mindfulness when consuming lassi to enjoy its benefits without unwanted drowsiness. Additionally, avoiding sweetened versions and late-evening consumption can help mitigate sleepiness.