Absorption
Bioavailability
Also searched as Bioavailability.
You want it high: bioavailability is what turns an ingredient into an effect — the whole point of 200:1 concentration.
In depth
The absorbable fraction of a nutrient — how much of what you take actually reaches the bloodstream to act.
What drives it
Phase-two glucuronidation reduces it.
First-pass conjugation is the main reason oral polyphenol bioavailability is low - the body treats them as xenobiotics. Carried by the intermediary-metabolism, micronutrient and clinical reviews. doi 10.3390/nu18132141 · PMC9967593
What it drives
It increases Micronutrient status.
Micronutrient-bioavailability review 2025, Front Nutr — the bioavailable (absorbable) fraction of a nutrient determines micronutrient status; low bioavailability drives inadequacy/deficiency despite intake. PMC12673670
It increases Liver clearance.
The aging outcome lists the thirteen hallmarks themselves, each mapped to its pathway and labeled with its hallmark number. (from the reviews of this outcome). Sources: PMC10132248; doi 10.1016/j.jhep.2023.03.017; PMC12673670. doi 10.1016/j.jhep.2023.03.017 · PMC10132248
It increases Skin.
Verbatim: “Furthermore, in mice, Gly-3Hyp-4Hyp was efficiently delivered to the skin after jellyfish collagen hydrolysate administration, showing a 19-fold greater accumulation compared with the bovine group, whereas other Hyp-containing oligopeptides exhibited minimal transport”. doi 10.1021/acs.jafc.6c08326 · PMID 42715523
It increases Liver detox.
First-pass CYP metabolism is a principal determinant of how much of an oral compound reaches the circulation. doi 10.1038/s41522-022-00352-6 · PMC10132248
It increases Thyroid.
The finding that reframes the whole node: the thyroid makes a pro-hormone, not the active hormone. T4 is activated to T3 by DIO1 and DIO2, and inactivated to rT3 by DIO3 - and the three types of deiodinases have variable tissue distribution, so active hormone level is set locally in each tissue, not centrally by the gland. A serum TSH does not tell you what a given tissue is seeing. Three trace elements, three different jobs: thyroid and deiodinase function depends on supply of the trace elements iodine, selenium and iron. Iodine is the substrate; selenium because the deiodinases ARE selenoproteins; iron because thyroperoxidase is a hemoprotein. A thyroid formula missing any one of the three has a hole in a different place. And selenium carries a documented harm: in a small fibrous gland with low iodine intake, SE supplementation for six months resulted in severe hypothyroidism with very low total T4 and highly elevated TSH - because activating previously-selenium-starved extrathyroidal deiodinases accelerated the loss of limited iodine stores. Selenium without sufficient iodine can make thyroid function worse. Genetic variation is named: the DIO2 Thr92Ala polymorphism may impair T4-to-T3 conversion in certain individuals. doi 10.1016/j.freeradbiomed.2022.09.024 · PMC9967593
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.