Magnesium, L-Theanine, Melatonin, Glycine: Four Evening Ingredients, Explained

Evening supplements can feel like a confusing menu: the same words show up in different dosages, formats, and blends. The quickest way to make sense of it is to understand the ingredient categories first.

These four show up again and again in sleep-focused routines: magnesium, L-theanine, melatonin, and glycine. They’re not interchangeable, and they’re often used for different reasons.

Magnesium: a mineral with many label names

Magnesium is a mineral, and the “form” on the label usually describes what it’s paired with. You’ll see names like glycinate, citrate, malate, and oxide. That form language matters because it changes what you’re comparing across products and how the product is positioned.

Magnesium also shows up in food—nuts, seeds, legumes, leafy greens—so some people think about it as part of a broader routine rather than a single ‘one-and-done’ decision.

L-theanine: the calm-tea association

L-theanine is commonly associated with tea culture. People tend to describe it in routine terms: they like how it fits alongside a calmer evening hour or a less-stimulating night.

It often appears as a single ingredient and also as a supporting ingredient in blends, which can make labels look deceptively similar.

Melatonin: a timing-focused category

Melatonin is a timing keyword as much as it is an ingredient. You’ll see “time release” and “fast dissolve” formats, and the product design usually signals how the brand expects it to fit into a routine.

Because the category is timing-oriented, people often think about it differently from minerals and amino acids. The conversations tend to revolve around schedule shifts, travel, and bedtime consistency.

Glycine: the quietly popular amino acid

Glycine doesn’t have the buzz of louder categories, but it shows up because it’s simple and often sold as a single ingredient. People who already think in amino-acid categories tend to find it easier to understand than complex herbal blends.

Powders are common here, which means the routine feel can be very different from a capsule-based routine.

Blends: convenience vs clarity

Many products bundle multiple ingredients together. That can feel convenient, but it can also make a routine less clear—especially if you prefer a minimalist setup or you want to know what you’d keep the same next month.

A practical approach is starting simple (one category at a time), then deciding whether a blend fits your style once you know what you actually enjoy using.

Where people get stuck

Most routines break at the same points: the plan is too ambitious, the environment doesn’t support it, or there’s no clear ‘default’ when life gets busy.

• Trying to fix everything at once: bedtime, workouts, caffeine, screens, and supplements in the same week.
• A weekend schedule that feels like a different time zone by Monday.
• Wind-down plans that are too long to repeat on a tired night.

A week-long experiment

If you want this to feel doable, pick one small move and keep it consistent long enough to become normal. The goal is not a perfect routine; it’s a repeatable one.

• Choose one wind-down anchor and keep it for five nights.
• Set a lights-down cue after dinner (lamp, warm light, fewer overheads).
• Keep weekend bedtime drift smaller than usual for one weekend.

Once the routine feels stable, you can add another layer. Stability first makes everything else easier.