How to compare L-cysteine prices

Comparing L-cysteine prices by the bottle, or even by the capsule, can be misleading, because commercial serving sizes range widely — commonly 250 mg to 1,500 mg per capsule across brands. A cheaper-looking bottle can work out to a higher price for the same gram of actual ingredient. Comparing on a price-per-gram basis puts different serving sizes on equal footing.

Why price per bottle isn't a fair comparison

Two bottles priced the same, with the same capsule count, can still deliver very different total amounts of L-cysteine if one uses 250 mg capsules and the other uses 1,000 mg capsules. Since no research has established an effective supplement dose for L-cysteine (see L-cysteine dosage), a higher milligram amount per capsule isn't a documented benefit either — but it does change how many grams of the ingredient you're actually paying for, which is what a price comparison should account for.

The math: price per gram

The calculation is: total bottle price ÷ (serving size in grams × number of servings in the container) = price per gram of L-cysteine.

As a worked example with illustrative, made-up numbers: a bottle priced at $16.00 with 60 capsules at 500 mg (0.5 g) each contains 30 g of L-cysteine total, for a price of about $0.53 per gram. A second bottle priced at $12.00 with 60 capsules at 250 mg (0.25 g) each contains 15 g total, for a price of about $0.80 per gram — the "cheaper" bottle is actually the more expensive one per gram of ingredient, even though its sticker price is lower.

What to pull from the label to run the math

• The milligram amount per serving, from the supplement facts panel — not the marketing copy, which sometimes rounds or omits it.
• The number of servings per container, and whether a "serving" is one capsule or more than one.
• The total price, including whether it's a one-time or subscription price, since those can differ.

What price per gram doesn't tell you

It doesn't tell you whether a given amount does anything — no trial has established an effective daily dose to weigh the price against (see L-cysteine dosage). It also doesn't account for the capsule's other ingredients, sourcing, or testing; see how to choose a good L-cysteine for the rest of the checklist. Price per gram answers one narrow question — which product gives more ingredient for the money — not whether that ingredient is worth buying at all.

Questions people ask

How much should an L-cysteine supplement cost?

There's no benchmark price, since cost varies by brand, sourcing, capsule count and serving size. Price per gram (above) is a more useful comparison than the bottle price alone.

Why do two L-cysteine bottles with the same capsule count cost different amounts?

Usually because the milligram amount per capsule differs, along with sourcing, manufacturing, and other ingredients — check the supplement facts panel on each rather than assuming "capsules" means "the same amount of L-cysteine."