If you're two drinks in and already feeling noticeably more affected than the people around you, there's a good chance it's not a coincidence — and it's not just about how much you've eaten or how big you are.

For a significant portion of the population, the answer is genetic.

It's Probably Not About Tolerance

Most people assume getting drunk faster comes down to weight, experience, or how much they've eaten. Those factors do matter. But if you consistently feel the effects of alcohol more intensely and more quickly than others — even friends of similar size — something else is likely at play.

The most common genetic explanation is ALDH2 deficiency: a variant in the gene that codes for the enzyme responsible for breaking down acetaldehyde, alcohol's primary toxic metabolite.

What ALDH2 Deficiency Does to Your Drinking Experience

Here's what happens when you drink:

1. Alcohol is converted to acetaldehyde in the liver by alcohol dehydrogenase (ADH)
2. Acetaldehyde is then converted to harmless acetate by ALDH2
3. If ALDH2 doesn't work efficiently, acetaldehyde builds up rapidly in the bloodstream

Acetaldehyde is significantly more toxic than alcohol itself. It triggers histamine release, dilates blood vessels, and produces an amplified physiological response. That's why people with ALDH2 deficiency experience intense symptoms — flushing, racing heart, nausea, dizziness — from amounts of alcohol that most people barely feel.

People with one deficient ALDH2 allele (heterozygotes) have less than 20% of normal enzyme activity. People with two deficient alleles (homozygotes) have virtually none. Both groups have significantly elevated acetaldehyde levels after drinking.

Why It Feels Like Being More Drunk

Acetaldehyde creates a distinct physiological profile that overlaps heavily with being drunk — but it's actually a toxic response, not just intoxication. The symptoms are similar: warmth, lightheadedness, impaired coordination. But the mechanism and the downstream health implications are different.

People with ALDH2 deficiency aren't simply lightweight drinkers. Their bodies are producing a more intense systemic reaction to the same amount of alcohol.

Other Reasons People Get Drunk Faster

ALDH2 deficiency is particularly common in people of East Asian descent, affecting around 35–40% of Chinese, Japanese, and Korean populations. But it's not exclusive to East Asians — estimates suggest over 120 million people worldwide outside East Asia carry ALDH2 variants that reduce enzyme activity.

Other contributing factors include:

Body composition: Water dilutes alcohol. People with lower body water percentage — including those with less muscle mass — reach higher blood alcohol concentrations from the same dose.

Genetics affecting ADH: Some people have faster-acting alcohol dehydrogenase, meaning ethanol is converted to acetaldehyde more rapidly. Combined with slower ALDH2 clearance, this amplifies the effect.

Hormonal fluctuations: For women, alcohol is metabolised differently across the menstrual cycle, and oestrogen affects gastric ADH activity.

Age and liver changes: Liver enzyme activity changes with age. People in their 40s and 50s often notice they handle alcohol differently than they did in their 20s.

What to Do About It

If ALDH2 deficiency is the cause, the approach is to support acetaldehyde clearance rather than just accept the reaction.

Antioxidants like glutathione, NAC, and R-Alpha Lipoic Acid — the core ingredients in iBlush — support the metabolic pathway that should be clearing acetaldehyde. Taking them before drinking helps your body process what the impaired ALDH2 enzyme can't handle efficiently on its own.

Beyond supplementation: drink more slowly, eat before drinking, alternate with water, and choose lower-congener drinks (clear spirits over dark ones, white wine over red).

iBlush tablets, patches, and gel are specifically formulated for people whose bodies respond more intensely to alcohol — regardless of how you'd label that experience.

P.S. We did the research so you don't have to:

1. Heterozygous ALDH2*1/*2 individuals have less than 20% of normal ALDH2 activity. Forman D, et al. (2025). Cancer Epidemiology, Biomarkers & Prevention. https://pmc.ncbi.nlm.nih.gov/articles/PMC12048207/
2. Acetaldehyde is up to 30x more toxic than alcohol itself. iBlush Ingredients & Benefits (October 2025). https://iblush.com/en-us/blogs/news/iblush-ingredients-and-benefits
3. Over 120 million non-East Asian individuals globally carry ALDH2 variants. Li H, et al. (2009). Refined geographic distribution of the oriental ALDH2*504Lys variant. Ann Hum Genet, 73:335–345.
4. Prevalence of ~35–40% in East Asian populations. Harada S, et al. (1981). Journal of Studies on Alcohol, 42(1):1–10.