Alcohol affects people differently in part because biology and body composition shape how quickly alcohol is absorbed and processed. In many cases, males and females metabolize and distribute alcohol differently, which can influence how quickly the effects are felt. Key factors behind why some people—often described in terms of sex or gender—may experience alcohol effects more slowly or less intensely include:

• Body water content: Men generally have a higher total body water percentage than women. Since alcohol distributes in body water, a given amount of alcohol becomes more diluted in a person with more body water, leading to lower blood alcohol concentration (BAC) for longer periods after the same dose. This can blunt and delay noticeable effects in men relative to women with the same body weight and dose. Conversely, people with lower body water may reach higher BAC more quickly, intensifying effects sooner. [health.cornell.edu]
• Body size and composition: On average, men have larger bodies and more lean mass, which can dilute alcohol more than in smaller-bodied individuals. More mass to distribute across can reduce BAC, slowing the onset of impairment. [health.cornell.edu]
• Enzyme activity (gastric alcohol dehydrogenase, ADH): A portion of alcohol is metabolized in the stomach before reaching the bloodstream. People with lower gastric ADH activity will have more alcohol pass into the blood, raising BAC sooner. Studies have found that, on average, women may have lower gastric ADH activity than men, contributing to higher BAC after the same amount of alcohol. This difference helps explain why women can become intoxicated more quickly. [health.cornell.edu][pmc.ncbi.nlm.nih.gov]
• Hormonal influences: Hormonal fluctuations across the menstrual cycle, use of hormonal contraceptives, and other endocrine factors can affect how quickly alcohol is absorbed and eliminated, sometimes prolonging peak intoxication in female-bodied people for certain windows. [health.cornell.edu][pmc.ncbi.nlm.nih.gov]
• Metabolic rate per body mass: Some research suggests that, per unit of lean body mass, women may eliminate alcohol differently than men, which can influence how long impairment lasts. However, total elimination over time tends to be similar when adjusted for body mass, though the rate and pattern can differ. [pmc.ncbi.nlm.nih.gov]
• Body fat percentage: Higher body fat can influence how alcohol distributes in the body. Since alcohol is not stored in fat, individuals with higher fat percentages may reach higher BAC more quickly for a given dose than those with more lean mass, potentially altering both onset and duration of effects. [health.harvard.edu]

How this translates to practical differences:

• After the same amount of alcohol, many women reach higher BAC faster and may experience stronger impairment sooner than men of the same weight. This can feel like the effects come on more quickly or more strongly for some women. [web sources on gender differences]
• Conversely, men with higher body water and lean mass may metabolize and clear alcohol somewhat faster, potentially delaying peak impairment compared with some female peers of similar weight. [web sources on gender differences]

Important caveats:

• Individual variation is large. Age, health, liver function, medications, drinking history, food intake, and genetics can all shift how alcohol affects a given person. [cdc.gov]
• These patterns describe average differences; they do not apply identically to every person. Always drink responsibly and be aware of personal limits. [cdc.gov]

If you’d like, I can summarize the latest guidelines for safe drinking by gender and body size, or tailor the explanation to a specific context (e.g., athletic performance, pregnancy, or medication interactions).