Water that helps you sleep?

I came across an advert yesterday for a product called Dream Water. It claimed to be a new drinkable product that helps you sleep. Naturally, I was skeptical. According to the website, the product claims to have three essential ingredients that make it work:

1) GABA, or gamma-amino butyric acid, an inhibitory neurotransmitter
2) melatonin, a hormone
3) 5-HTP, 5-hydroxytryptophan, a serotonin and melatonin precursor

Here are my thoughts:
GABA is pervasive throughout the brain, and its role in sleep is a teeny, tiny slice of the entire pie. It's a hard sell to tell someone that taking GABA systemically will act to suppress the wake-promoting centers in a significant way. Furthermore, GABA isn't believed to cross the blood-brain barrier. So when you drink it, it never gets to your brain anyway. (As a side note, the website claims GABA 'prevents over-firing of nerve cells' and 'can help induce tranquility'. It is implied that your brain is quiescent during sleep, which is false.)

I did some searching, and a study from 1971 found that 5-HTP leads to increased REM sleep in eight normal humans. However, increased REM sleep is not equivalent to increased sleep quality, especially for someone that is sleep-deprived. Instead, an increase in slow wave (non-REM) sleep is believed to be indicative of recovery from sleep deficiency. (5-HTP was also associated with vivid dreams and nightmares.)

Melatonin is available as an over the counter supplement, and is commonly suggested by doctors for those that have trouble sleeping. Melatonin levels in the body naturally rise at night, and is believed to be a strong marker of your circadian rhythm. Thus, if you take melatonin before bed when your body's clock is shifted a couple hours later (as in the case of west-to-east jetlag), taking melatonin may help reset your clock quicker.

My conclusion? I say, drink Dream Water if you'd rather drink your melatonin than swallow it.

Source:
Wyatt et al. Electroenceph Clin Neurophys 30, 1971.