Every supplement in our catalog carries a dose range, and many carry something people respect less: a ceiling. Past it, the supplement stops being neutral and starts costing you.
These are the 10 ceilings most worth knowing, with what actually happens above each one.
The 10 that matter
All numbers are daily totals from our catalog. A few count all sources including food; most count supplements alone.
- Zinc: 40 mg. Chronic intake at 50 mg or above depletes copper
- Selenium: 400 mcg. Excess causes selenosis: garlic breath, brittle nails, fatigue
- Vitamin A: 10,000 IU. Preformed retinol is toxic high, and teratogenic in pregnancy
- Vitamin D: 4,000 IU. Toxicity comes from supplements, essentially never from sun
- Iron: 45 mg. Excess is harmful and invisible without blood work
- Folic acid: 1,000 mcg synthetic. Above it, B12 deficiency can hide
- Magnesium: 350 mg elemental from supplements. Food magnesium doesn't count
- Caffeine: 400 mg. The level safety agencies call the adult daily limit
- Melatonin: 5 mg. More rarely helps; the lowest effective dose wins
- Calcium: 2,000 to 2,500 mg from all sources. Excess raises kidney stone risk
Where doubling hides
Almost nobody crosses these ceilings with one bottle. They cross them with three: a multivitamin, a fortified protein powder, and a standalone supplement of the same nutrient.
The catalog has built-in examples. A B-complex already contains B12 and folate. Shilajit naturally contains iron. Two magnesium forms count toward one elemental total.
The fix is one label-reading session: add up everything you take per nutrient, once, and you'll know exactly where you stand.
The food distinction
Ceilings differ on what they count. Magnesium's 350 mg and folic acid's 1,000 mcg apply to supplements and fortified foods only; spinach and lentils are exempt.
Calcium counts everything, dairy included. This is why the same number can be fine for one person's diet and over the line for another's.
Dose to the range, not past it
More is not a hedge. For most nutrients the benefit curve flattens inside the recommended range, while the risk curve keeps climbing past the ceiling.
Suplagen enforces these caps automatically across your whole stack, which is exactly the arithmetic most people never do by hand.
General information, not medical advice. Talk to a clinician before starting a new supplement, especially if you take medication or are pregnant or nursing.
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