Every absorption study leans on a handful of terms — bioavailability, AUC, Cmax, Tmax. Learn to read them and you can judge a supplement claim for yourself instead of taking anyone's word for it.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. This page is educational, not medical advice — talk to a licensed clinician about your own situation.
When a bottle says 500 mg, that's the dose — how much you swallow. It says nothing about how much actually makes it into your bloodstream in a form your body can use. That second number is bioavailability, and it's almost always smaller. Sometimes dramatically so.
Bioavailability is the fraction of a dose that reaches systemic circulation intact. A nutrient has to dissolve, survive stomach acid and digestive enzymes, cross the intestinal wall, and get past the liver — which filters everything absorbed from the gut before it reaches the rest of you. Each step takes a cut.
This is why two products with the identical dose on the label can deliver wildly different amounts to your cells, and why 'more milligrams' isn't the same as 'more nutrient.' Once you understand the vocabulary of absorption, supplement marketing gets a lot easier to see through.
Dose is what you swallow. Bioavailability is what you actually get. They're rarely the same number.
Follow a single dose from the moment you swallow it. At each checkpoint, some is lost — and only what survives the whole gauntlet counts as bioavailable.
The full amount printed on the label. This is the starting line, not the finish.
Some compounds dissolve poorly or break down in stomach acid before they can be absorbed at all.
Only a portion of what's dissolved actually passes through the gut lining into the body.
Everything absorbed from the gut hits the liver first, which chemically alters or removes a large share before it ever circulates.
What's left is the bioavailable fraction — the part that can actually reach your tissues and do something.
Illustrative percentages to show the shape of the problem; real losses vary enormously by nutrient and formulation. Some compounds clear these hurdles easily; fragile or fat-soluble ones often don't.
Here's the step most people never hear about. Everything absorbed from your gut doesn't go straight into general circulation — it's routed first, through the portal vein, directly to the liver. The liver's job is to screen what comes in, and it chemically alters or removes a big share before the rest is allowed through. That detour is called first-pass metabolism, and for many nutrients it's where most of the dose disappears.
Absorbed dose flows gut → portal vein → liver, where a large fraction is metabolized before the remainder reaches the bloodstream.
To be absorbed at all, a nutrient has to cross the intestinal lining — a wall built from phospholipid membranes. Water-soluble compounds struggle to pass through a fatty barrier; fragile ones get degraded before they can. This is exactly the bottleneck a lipid carrier is built to solve: wrap the nutrient in the same phospholipids the membrane is made of, and it can merge straight through.
A nutrient carried in a phospholipid shell merges with the membrane and passes into the bloodstream, instead of being blocked or broken down.
Absorption studies plot the concentration of a nutrient in the blood over time after a dose. Three numbers describe that curve — once you know them, you can read almost any bioavailability study.
The highest blood level the dose reaches. A higher Cmax means more nutrient hit your bloodstream at the peak.
How long after the dose that peak arrives. It tells you how fast a formulation is absorbed.
Total exposure over time — the single most important number. It captures both how high the level got and how long it stayed up.
Many nutrients need to stay above a threshold to matter. A curve that peaks high but drops fast can spend less time where it counts than a lower, steadier one.
The words that show up again and again in delivery research — defined without the jargon. Tap any card for a concrete example.
Here's the whole lesson in one chart: an identical dose delivered two ways. The formulation with the larger area under the curve — higher and more sustained — delivered more total nutrient, even though the milligrams on the label were the same.
Illustrative curves to show how AUC, Cmax and Tmax read on a chart — not data from a specific product.
The methods of measuring absorption are mature and standardized. How much any given nutrient benefits from better delivery is where the variation lives.
Each dot is one finding below — the further left, the more settled the science. We placed them honestly: absorption is well-supported; downstream outcomes are still earlier-stage.
The liver's first-pass filtering is a well-characterized reason many oral compounds have low bioavailability — and a big part of why delivery strategy matters as much as dose.
Human pharmacokinetic studies have shown that lipid-based and liposomal delivery can increase the area under the curve for poorly absorbed nutrients like vitamin C versus a standard dose. The effect is real and measurable — and formulation-specific.
This is the lens behind everything Manna builds. We don't compete on how many milligrams we can cram onto a label — that's the easy number to inflate and the least meaningful. We care about AUC: how much nutrient actually reaches your bloodstream, and how long it stays there.
That's why we lead with liposomal and lipid-based delivery. We're not here to promise an outcome or a dose — that's between you and your clinician. We're here to make sure delivery isn't the reason a good ingredient quietly underperforms.
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. This page is educational, not medical advice — talk to a licensed clinician about your own situation.
