mcg, mg, IU, DFE, RAE: A Label Unit Decoder
Five units appear on supplement panels and three of them describe the same nutrient in different ways. What each one means and how to convert between them.
2026-09-01 · 8 min read · Units
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Thirteen Articles, Free To Read
Mechanism, label literacy and the free habits that outrank any supplement. Several of these argue against making a purchase.
01The Articles
Newest first
No sign-up, no email capture, no paywall.
Why Supplements Contain 5000 mcg Of Biotin
A hundred and sixty times the daily requirement, in a nutrient with no upper limit. Where that number came from, whether it does anything, and the one real consequence.
2026-08-28 · 8 min read · Biotin
What Vitamin C Actually Does To Collagen
Not a metaphor and not marketing. Two enzymes physically cannot function without it, and scurvy is what happens when they stop.
2026-08-24 · 8 min read · Collagen
Vitamin D: The One Your Skin Makes And Winter Takes Away
Above a certain latitude your skin cannot make vitamin D at all for several months a year, whatever the weather looks like. What that means for skin specifically.
2026-08-20 · 8 min read · Vitamin D
Zinc: The Mineral With The Longest Dermatology Record
Several hundred enzymes need it, one inherited deficiency disease made the case beyond argument, and the reason good formulas keep the dose small is copper.
2026-08-16 · 8 min read · Zinc
Vitamin E: What It Really Does, And What It Does Not
An antioxidant that works by being destroyed. Why the mechanism is simple, why the high-dose trials disappointed, and where the bleeding caution comes from.
2026-08-12 · 7 min read · Vitamin E
Thirteen Nutrients Or Three: Which Is The Better Buy?
Broad formulas and targeted single-nutrient products solve different problems. How to tell which one your situation calls for.
2026-08-08 · 8 min read · Strategy
Who Actually Needs A Skin Supplement?
A self-assessment that will tell a lot of readers to keep their money, written by a site that earns a commission when they do not.
2026-08-04 · 8 min read · Self-check
Shedding Or Losing? Two Different Problems
One resolves on its own in months, the other does not. Telling them apart decides whether a supplement is even the right category of answer.
2026-07-31 · 8 min read · Hair
What Your Nails Are Actually Telling You
Nails grow slowly enough to record several months of your health. Which changes mean something, which mean nothing, and which need a doctor.
2026-07-27 · 7 min read · Nails
Gummy Or Tablet? The Trade-Offs, Counted
Sugar, stability, dose ceilings and whether you actually take it. Four differences that matter and two that do not.
2026-07-23 · 7 min read · Format
How To Test Whether A Supplement Works For You
Photographs, one variable at a time, and the mismatch between a twelve week verdict and a sixty day refund window.
2026-07-19 · 7 min read · Testing
Heat, Damp And Light: Storing A Bottle Properly
Why gummies fuse, why the fridge is the wrong answer, and what an expiry date on a supplement actually promises.
2026-07-15 · 6 min read · Storage
What this section is for
Most of what decides how skin looks has nothing to do with a supplement. Ultraviolet exposure, sleep, how hard you strip your face at the sink, indoor humidity and what is on your plate all matter more than any bottle, and nearly all of them cost nothing.
So the mechanism articles here explain what individual nutrients genuinely do rather than what they are sold as, and the buying articles teach label literacy, because reading a panel properly is a skill that protects you in a category where a great deal of nonsense is marketed with confidence. %s is mentioned where it is genuinely relevant and left out where it is not.
Where to start
- If two labels will not compare cleanly: the unit decoder. Nothing else here is as immediately useful.
- If you are wondering whether you would benefit at all: the self-assessment, which will tell a lot of readers to keep their money.
- If a blood test is coming up: the biotin article.
- If your hair is coming out: shedding or loss, and the difference decides everything that follows.
- If you want the mechanism rather than the marketing: what vitamin C does to collagen is the clearest example in the whole panel.
Nothing here sits behind an email form and nothing requires an order. If the only thing you take away is a habit of converting units before comparing two bottles, that is a good outcome.
03More
Elsewhere On This Site
Your First Bottle Of Gelagen
Two gummies with breakfast, a page on this site for every amount printed on the panel, and two months to send the lot back if your skin disagrees.
- Two gummies daily, chewed rather than swallowed
- Thirteen nutrients, every amount printed on the bottle
- Free US delivery and six guides on the 3 and 6 bottle orders
- Sixty days to change your mind, opened bottles included
