Moderation doesn’t work because of the way alcohol works.

Alcohol, also known by its chemical name ethanol, is a psychoactive substance that is the active ingredient in drinks such as beer, wine, and distilled spirits (hard liquor). It is one of the oldest and most common recreational substances, causing the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces a mood lift and euphoria, decreased anxiety, increased sociability, sedation, impairment of cognitive, memory, motor, and sensory function, and generalized depression of central nervous system function. Ethanol is a type of chemical compound known as an alcohol, and is the only type of alcohol that is found in alcoholic beverages or is commonly used for recreational purposes; other alcohols such as methanol and isopropyl alcohol are toxic. Alcohol has a variety of short-term and long-term adverse effects. Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and hangover-like symptoms. Alcohol can be addictive to humans, as in alcoholism, and can result in dependence and withdrawal. It can have a variety of long-term adverse effects on health, for instance liver damage, brain damage, and increased risk of cancer. The adverse effects of alcohol on health are most important when it is used in excessive quantities or with heavy frequency. However, some of them, such as increased risk of certain cancers, may occur even with light or moderate alcohol consumption. In high amounts, alcohol may cause loss of consciousness or, in severe cases, death. Alcohol works in the brain primarily by increasing the effects of a neurotransmitter called γ-aminobutyric acid, or GABA. This is the major inhibitory neurotransmitter in the brain, and by facilitating its actions, alcohol suppresses the activity of the central nervous system. The substance also directly affects a number of other neurotransmitter systems including those of glutamate, glycine, acetylcholine, and serotonin. The pleasurable effects of alcohol ingestion are the result of increased levels of dopamine and endogenous opioids in the reward pathways of the brain. Alcohol also has toxic and unpleasant actions in the body, many of which are mediated by its byproduct acetaldehyde. Alcohol has been produced and consumed by humans for its psychoactive effects for almost 10,000 years. Drinking alcohol is generally socially acceptable and is legal in most countries, unlike with many other recreational substances. However, there are often restrictions on alcohol sale and use, for instance a minimum age for drinking and laws against public drinking and drinking and driving. Alcohol has considerable societal and cultural significance and has important social roles in much of the world. Drinking establishments, such as bars and nightclubs, revolve primarily around the sale and consumption of alcoholic beverages, and parties, festivals, and social gatherings commonly feature alcohol consumption as well. Alcohol use is also related to various societal problems, including driving accidents and fatalities, accidental injuries, sexual assaults, domestic abuse, and violent crime. Currently, alcohol is illegal for sale and consumption in Iran, Libya, Sudan, Saudi Arabia, Kuwait, Afghanistan, Somalia, Yemen, and Bangladesh.