Equanox is a product manufactured by The Zaibatsu Corporation that was advertised on the radio in Grand Theft Auto III. It is a "wonder drug" that, according to Zaibatsu, combats dissatisfaction, lethargy, depression, melancholy, sexual dysfunction and "just about anything"; however, it comes with a long list of side-effects. According to an article from the Liberty Tree, the drug was initially banned by the FDA for causing psychotic behavior in rats and being "synthetically like PCP, only more toxic". It is similar to another Zaibatsu product, Zoom Zoom, that was advertised in Grand Theft Auto 2.
It may be a horse tranquilizer, as it combines the Latin term of 'equus', which means horse, and 'nox', which roughly translates from Latin to 'night'.
Woman: I used to be concerned and nervous about the future. Sometimes I'd get scared before an important event, such as childbirth, or a family funeral. Hey, sometimes you need a little help navigating life's trouble spots! That's when I discovered Equanox!
Man: After the divorce and losing little Tommy, life was getting me down. I couldn't focus on anything at work. After trying Equanox, I've been employee of the month three times in a row!
Man #2 : I used to fall unconscious for hours at a time, but now with Equanox, I never need to sleep.
Man #3 : Eqaunox is new, from Zaibatsu Pharmaceuticals. Ask your doctor about Equanox... Today!
Disclaimer: Equanox may cause nausea, loss of sleep, blurred vision, leakage, kidney problems and breathing irregularities. Do not take Equanox if you are operating any machinery, driving a car, pregnant, a child of low age, unhappy or if your family has a history of mental disorders.
Man #3: Equanox. Softening life's harsh realities!