On the other hand, their radio ad claims that "users have compared the effect of Zentra to falling in love" or "an overwhelming sensation that all is well in the world, and things are getting better" (paraphrased, I don't remember the exact terms from the ad, but they were similarly glowing). Note that the producers don't claim themselves that Zentra has these effects, they just say that some customers report them.
This strikes me as a dodgy, sneaky ad campaign designed to separate people with mental health issues from their money by hinting -- if not actually promising -- that their product is as effective as real depression medication without the side-effects associated with real medication, which they make sure to say Zentra doesn't have.
Reader SKN990 directed me to the ingredient listings for the two Zentra supplements.
Zentra Complete utilizes a proprietary formula derived from b-vitamin molecules which an excellent source of energy, feelings of overall wellness and calm, improved memory, focus and concentration without the side effects of caffiene.Zentra Daily (Day Time Stress Relief Formula) contains magnolia bark extract (standardized for honokiol), Phenibut, GABA, and Picamilon.
Zentra Complete (Night Time Stress Relief Formula) contains Vitamin B12, Sulbutiamine (a vitamin B1 derivative), and Pyrithioxine (a vitamine B6 derivative, also known as Pyritinol).
A study published on PubMed does show reduction in some stress indicators in rodents from a mixture of honokiol and magnolol (another compound extracted from magnolia bark), although I have no idea how the dosage in the mice compares to the dosage in Zentra for humans.
Phenibut apparently also has real effects on mood in mice.
GABA is gamma-Aminobutyric acid that apparently functions as a neurotransmitter, although I can’t claim to understand neurochemistry well enough to properly interpret the extract of the article.
Picamilon is a combination of GABA and niacin (vitamin B3), and one study describes it as a known nootropic: a drug that enhances cognition, memory, attention, motivation, and concentration.
A study of sulbutiamine says, “Sulbutiamine has no antidepressive effect but it can… facilitate the rehabilitation of patients in their social, professional and family life functioning.”
Pyrithioxine is lab-created variant of vitamin B6 that apparently does have some effect on chemical activity in the brain, as well.
All-in-all, it looks like Zentra could legitimately affect a person's mood and relieve depression. I do not see any studies or evidence to support the glorious language used in their advertising, however. Some of the ingredients are listed as over-the-counter or even prescription medications in some countries, although Zentra is being sold as a dietary supplement in the US with claims that it is perfectly safe to use. Given that some of its contents really do seem to have chemical effects in the brain, I would hesitate to say that it's perfectly safe, although it is probably quite low in risk (especially at the doses they're probably recommending).
In a nutshell, if Zentra affects mood as much as their advertising implies (and they make it sound like heroin with their talk of "blissful" sensations), it's probably not perfectly safe. On the other hand, if it's perfectly safe, it's probably not as effective as they want you to think.