Melatonin is a hormone your brain already makes. Most sleep products add 10 to 30 times more than your body produces naturally. A 2025 study from the American Heart Association found that people who used melatonin for over a year had a 90% higher risk of heart failure. A 2023 study in JAMA tested 25 melatonin gummies and found that 22 of them contained the wrong dose, some with up to 347% of what the label claimed. The American Academy of Sleep Medicine, the leading medical authority on sleep, officially recommends against melatonin for adults with sleep problems. We don't use it because we are a sleep brand, not a hormone brand.

L-tryptophan is the building block your body uses to make melatonin. Many sleep brands include it at 200mg and call it "natural sleep support". The result is the same as taking melatonin directly: your body produces more sleep hormone than it should. If we say no to melatonin, we also have to say no to the back door that leads to it.

GABA is the calming chemical messenger your brain uses to slow down. Taken as a supplement, it sounds perfect. The problem: oral GABA barely crosses the protective wall around your brain, so most of it sits in your bloodstream doing nothing. It looks great on a label. It doesn't work where it counts. Apigenin works on the same calming receptors and actually reaches the brain. So we use that instead.

Reishi shows up in almost every sleep product. We considered it for the first version of SF Zero. We removed it after looking at the research. Most reishi sleep studies are in mice, not humans. The few human studies are small or test reishi alongside other mushrooms, so you can't see what reishi alone actually does. A 2024 review of 17 trials rated the evidence quality as "very low" for every outcome measured. To make our cut, an ingredient needs human research behind it.

Zinc is an important mineral for your immune system. It's often added to sleep products to make the label look more complete or to claim "immune support". The problem: zinc has no strong link to sleep, and it actually competes with magnesium for absorption. Adding zinc would reduce how much magnesium your body can use. On top of that, zinc on an empty stomach before bed often causes nausea. Wrong ingredient, wrong moment.

The cheapest form of magnesium on the market, often hidden inside "magnesium blends" so brands can put "magnesium" on the label without paying for the form that actually works. Your body only absorbs about 4% of magnesium oxide. The rest goes through you without doing anything. Real magnesium glycinate, the form we use, absorbs many times better and is gentle on the stomach. Same mineral. Very different result.

A sugar substitute often used in low-calorie products. The two reasons we left it out: first, a 2023 study in Nature Medicine linked higher erythritol levels in the blood to nearly double the risk of major heart events like heart attack and stroke over three years. Second, erythritol leaves a cool, mint-like aftertaste in warm drinks. That's why many sleep cocoa products taste off in the last sip. We chose monk fruit instead. Sweet, clean, no aftertaste, no safety questions.

A cheap powder made from corn or rice that bulks up products so the scoop weight looks more impressive. It spikes your blood sugar faster than table sugar, with a glycemic index around 95 to 110. Eating something that spikes your blood sugar right before bed is exactly the wrong way to fall asleep. A 2023 review also found that maltodextrin negatively affects gut bacteria in many people. Most sleep products contain it. We left it out, which is why our scoop is smaller. Everything in our scoop is doing something.

A regulatory term that lets brands hide almost anything behind two words. Under FDA rules, "natural flavors" can contain dozens of unnamed compounds, made in a lab as long as the starting material was once natural. Solvents, preservatives, and flavor extracts all qualify. If you can't read it on the label, you can't know what you're drinking. We name every ingredient in SF Zero, including the vanilla, the salt, and the lecithin. No two-word shortcuts.