A 10 oz glass of vodka has 118ml of ethanol in it. That works out to 93 grams of ethanol. Most other recreational drugs are measured in mg, ethanol is measured in grams.
With a MW of 46, that means 93 grams of ethanol (10oz of vodka) has about 10^24 molecules of ethanol.
For a drug like xanax, where 1mg is sufficient for a dose, that works out to roughly 10^18 molecules of xanax.
Since there are about 10^13 cells in the human body, why does ethanol require a dose that is roughly between a hundred thousand and a million times more molecules than many other recreational drugs to have an effect? Most other drugs (recreational and medicinal) are measured in mg. Ethanol’s dosage is measured in grams.
I’m going to go ahead and take a stab at this … more of a brain-storming session than an actual factual answer …
Ethanol is available in the environment and over evolutionary timescales life has had to be able to deal with it … glucose can be catalysed in the presence of ADP to form ethanol and ATP, which as I understand predates respiration … so with the advent of multicellular life, the mechanics to process ethanol into a safe waste product had already been established …
Jump forward a half billion years and now humans have the ability to create chemicals that are specifically engineered to be powerful and quick acting in very small doses … Lysergic acid is available in nature, but it needs to be brought into the chemical lab (or someone’s bathtub) and be made into LSD to gain it’s powerful effects … there’s no evolutionary mechanism to safely process the drug, and that’s by design …
Being able to safely process small amounts of ethanol is a requirement to life, thus humans need much larger amounts to gain the intoxicating effects …
Its got a lot of work to do as each receptor for acetylcholine, serotonin, GABA, and NMDA for glutamate can have an ethanol molecule attached. So there’s got to be a lot of molecules to go around. But the effect is limitted, as it doesn’t totally disable any. It alters them slightly. So that might be where there is an evolutionary tolerance … these receptors aren’t totally jammed up by ethanol. That means after some dose, there’s no more effect …
But also ethanol’s dopamine effect occurs when it blocks the enzymes that breaks down dopamine, which may be dose based… that might be why it takes so much to get sleepy drunk… you feel sleepy with higher dopamine .