Ipriflavone.
A made-in-a-factory isoflavone used for bone support. It acts on bone cells largely without hormonal activity, and the liver converts part of each dose into daidzein.
Reviewed March 2026
- Category
- Compound
- Also filed under
- Supports bone health
What Ipriflavone is, and what it does.
- Does it work
- It suits women through and after the midlife hormonal shift who already have calcium and vitamin D covered. If you drink a lot of coffee, read the caffeine note first.
- How much to take
- Start with 200mg a day alongside a meal that contains fat, where absorption is most reliable. 900mg split across the day is a trial condition rather than a daily target.
- Time to feel it
- Bone is slow tissue. Trials read bone density at twelve months and beyond, so this is followed on a scan rather than experienced week to week.
- The first dose
- Nothing surfaces on day one. Absorption is higher alongside a fat containing meal, and the liver reworks most of the dose before it reaches circulation.
- With regular use
- Bone remodels slowly. Trials ran twelve months and longer, reading density scans and bone turnover markers, so this is followed on a scan rather than week to week.
- How well tolerated
- Usually well tolerated, with occasional stomach upset. It slows the liver enzyme that clears caffeine and some medicines, and long trials tracked lymphocyte counts. Ask your doctor.
- How it feels
- There is no sensation to it. Bone remodels over months, so where this shows up is on a density scan and on bone turnover markers, not in how a given day feels.
- The overlooked benefit
- It slows CYP1A2, the enzyme that clears caffeine, so your usual coffee can hit harder and linger longer alongside it. Worth knowing before you blame the espresso.
200mg a day is where Ipriflavone works.
Source: Alexandersen et al. JAMA 2001; Agnusdei & Bufalino. Calcif Tissue Int 1997
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
While some studies suggest a positive effect on bone density, results are mixed, and further research is needed to confirm its efficacy. The mechanism is not fully understood.
- Bone mineral density in women in the years after their cycles endMeta-analysis
- Bone turnover markersRandomised trial
- Osteoclast formation and resorptive activityIn vitro study
- Inhibition of the liver enzyme that clears caffeineRandomised trial
Questions people ask about Ipriflavone.
- When should I take it?
- Timing matters less than consistency. Pick a time that works for you and take it daily.
- Can I take it with other supplements?
- Usually fine. The main thing to watch is not doubling up on the same ingredient from different products. If you're on prescription meds, check with your pharmacist first.
- Any side effects to watch for?
- Most people tolerate it well at recommended doses. GI upset is the most common complaint with any supplement. Start with a lower dose and work up. If something feels off, stop and reassess.
- Who benefits most from this?
- Honestly, most people would benefit more from the basics. But if you've got a specific reason to try it, the risk is generally low.
Why these belong in the same formula. Each row says what the basis is, from settled biochemistry through to a trial that measured the pair.
Ipriflavone acts on osteoclast activity and on osteoblast differentiation but supplies no mineral. Calcium provides the substrate that any change in bone turnover has to draw on, which is why the two are almost always dosed together.
Vitamin D raises intestinal calcium absorption through TRPV6 and calbindin, so it determines how much of the calcium dose reaches circulation. An isoflavone acting on bone turnover depends on that supply being adequate.
Osteocalcin has to be gamma-carboxylated by a vitamin K dependent enzyme before it can bind calcium into the bone matrix. Raising bone-forming activity without vitamin K leaves that final binding step incomplete.
About half of body magnesium sits in bone and it takes part in hydroxyapatite crystal formation as well as in parathyroid hormone signalling. It is a routine third mineral alongside calcium in bone formulations.
Boron influences calcium and magnesium retention and lengthens the half-life of circulating steroid hormones including estradiol. That places it beside an isoflavone acting on the same hormonal background in bone.
Strontium sits in the same lattice position as calcium in hydroxyapatite and shifts the balance of bone turnover. It also competes with calcium for intestinal absorption, so doses should be separated even while both serve bone.
Orthosilicic acid supports prolyl hydroxylase activity and type I collagen synthesis, which is the organic scaffold minerals deposit on. Bone formulas pair it with isoflavones and calcium to cover the matrix as well as the mineral.
One of the main circulating metabolites of ipriflavone is daidzein, the same isoflavone red clover and soy supply. Running both raises total isoflavone exposure at the same receptors, so the load should be counted once.
Ipriflavone and its metabolites inhibit CYP1A2, the enzyme that carries out most caffeine demethylation. The same caffeine dose then stays in circulation longer, which is settled pharmacokinetics rather than a theoretical concern.
Zinc is required by alkaline phosphatase and by the collagenases involved in bone remodelling, and it supports osteoblast differentiation. It sits alongside calcium as a supporting mineral in the same formulations.
Manganese is the cofactor for the glycosyltransferases that build the proteoglycans of cartilage and bone matrix. It is a small but genuine part of the matrix side that an isoflavone acting on turnover depends on.
Ascorbate is the required cofactor for prolyl and lysyl hydroxylase, the enzymes that hydroxylate collagen chains so a stable triple helix can form. Bone matrix is mostly type I collagen, so the mineral phase has nothing to deposit on without it. Ipriflavone acts on the cellular side of bone turnover, not on collagen chemistry, so the two address different parts of the same tissue.
Lysyl oxidase is a copper-dependent enzyme that forms the covalent cross-links giving bone collagen its tensile strength. Without adequate copper the matrix is laid down but not properly cross-linked. This is a nutrient requirement for normal bone matrix quality that sits alongside anything acting on bone cell turnover.
Collagen cross-links form at hydroxylysine and lysine residues, so lysine supply is part of matrix quality. It is also an amino acid whose intake has been linked to calcium retention. The pairing is a matrix-side complement to a bone-cell-side compound.
Proline is hydroxylated to hydroxyproline within the collagen chain, and that residue is what stabilises the triple helix. Bone matrix production draws on it continuously. Supplying it supports the protein side while other ingredients act on cell signalling or on the mineral.
Roughly half of bone mineral mass by formula is phosphate, so calcium alone cannot build hydroxyapatite. Phosphorus intake is usually adequate from diet, which is why supplements rarely add it. The relationship is stoichiometric and worth stating even when no supplementation is warranted.
Ipriflavone is 7-isopropoxyisoflavone, a synthetic modification of the isoflavone scaffold, and daidzein is one of its identified human metabolites. Taking soy isoflavones alongside it raises exposure to overlapping compounds rather than adding an independent one. Total isoflavone-class exposure, not just the ipriflavone dose, is the figure that matters.
Gamma-glutamyl carboxylase requires vitamin K to add carboxyl groups to osteocalcin, and only the carboxylated form binds calcium in bone matrix. Phylloquinone is the dietary form and is converted in tissue to menaquinone-4. Undercarboxylated osteocalcin in blood is a marker of vitamin K status, not an outcome in itself.
Ipriflavone has been characterised as an inhibitor of CYP1A2, and several catechin-rich extracts also interact with hepatic phase I enzymes. Stacking compounds that act on the same enzyme raises the exposure of anything else cleared by it. This is a pharmacokinetic caution about the pairing rather than a benefit claim.
Homocysteine interferes with lysyl oxidase-mediated collagen cross-linking, and folate together with B12 and B6 is what keeps homocysteine remethylated. Higher homocysteine has been associated with lower bone quality measures in observational work, which is an association and not a demonstrated cause. The pairing is a matrix-quality argument, not a bone-density claim.
Methylcobalamin is the cofactor for methionine synthase, the enzyme that remethylates homocysteine back to methionine. Low B12 raises homocysteine, which has been associated with weaker collagen cross-linking. The link to bone tissue runs through matrix chemistry and is an association at the population level.
Talk to a doctor before taking Ipriflavone if any of these apply to you: Pregnancy, Breastfeeding, Estrogen-sensitive conditions, Liver disorders. These are flags to check first, not effects Ipriflavone is known to cause.
Not medical advice. Show the label to your pharmacist.What Ipriflavone actually does.
Ipriflavone is 7-isopropoxyisoflavone, a synthetic compound built on the isoflavone scaffold; it does not occur in soy or any other food in meaningful amounts.
After oral dosing ipriflavone undergoes extensive first-pass hepatic metabolism to a set of identified metabolites, one of which is daidzein, the same isoflavone found in soy.
Any bone-cell-side compound acts on a tissue whose mineral phase is calcium hydroxyapatite deposited on a type I collagen scaffold, so calcium, phosphate, vitamin D, vitamin K and collagen substrate all remain rate-limiting independently.
Ipriflavone binds the classical oestrogen receptor only weakly compared with genistein and daidzein, which is why its actions on bone cells are described as largely non-hormonal.
Where Ipriflavone comes from.
This one is made in a factory, not pulled out of a plant. It looks like a soy compound and the body turns part of it into one, but the starting material is industrial chemistry and there is no soy anywhere in the process.
Chemically synthesised. The molecule is identical to the one a plant or an animal makes, and building it deliberately means a known purity, a fixed dose and no crop contaminants. For several nutrients this is the only route that reaches a usable amount.
The isoflavone core is built from substituted phenol and phenylacetic-type building blocks; nothing in the route starts from soy or any other plant.
The benzopyran-4-one core carrying a 3-phenyl substituent is assembled by established isoflavone synthesis chemistry, giving a hydroxylated isoflavone intermediate.
The 7-hydroxyl is alkylated with an isopropyl halide under base to give the isopropoxy ether, which is the structural change that defines ipriflavone and blunts its oestrogen-receptor binding.
Crude product is recrystallised from an organic solvent and residual solvents are stripped and tested against pharmacopoeial limits.
Identity and purity are confirmed by HPLC against a reference standard, and the powder is milled to a defined particle size distribution.
The dried powder is blended with excipients and compressed, encapsulated, or dispersed into a lipid carrier for a softgel.
Getting Ipriflavone from food.
The whole-food sources on file. A supplement closes the gap, it does not replace dinner.
A gram-for-gram figure (how much of each you would eat to match a dose) will appear here once it is sourced and reviewed. This page will not print a number it cannot cite.
The forms it comes in.
The essence, in one line each.
- Over 2 years in early postmenopausal women, ipriflavone at 600 mg a day, or 400 mg a day with low-dose conjugated estrogens, was followed by a rise in spinal bone density and a fall in urinary hydroxyproline, while bone density fell on calcium alone or low-dose estrogen alone.Randomised trial. Gambacciani et al., 1997 (Maturitas). PMID 9391998 ↗
- In a two-year multicentre double-blind trial, ipriflavone was compared with placebo on bone mineral density measurements in older adults with reduced bone density; the authors reported preservation of the density measure over the study period, which is a marker rather than a clinical outcome.Randomised trial. Maugeri et al., 1994 (Archives of Gerontology and Geriatrics). PMID 15374271 ↗
- A Cochrane review of herbal preparations for reduced bone density that names ipriflavone among the compared agents and concluded the available trial evidence was low quality and insufficient to support firm conclusions.Systematic review. Liu et al., 2014 (Cochrane Database of Systematic Reviews). PMID 24599707 ↗
- The study looked for a fall in lymphocyte counts with soy protein supplementation, a concern raised by earlier isoflavone work including ipriflavone, and did not detect one; a failure to detect a difference is not evidence that none exists.Randomised trial. Soung et al., 2006 (Nutrition Journal). PMID 16608514 ↗
These are the studies our verdict leans on, chosen from the 106 we read for Ipriflavone. The full linked list is below.
The studies, linked.
1 source behind our Ipriflavone verdict: peer-reviewed studies and registered clinical trials. Every one links straight to PubMed, the journal, or ClinicalTrials.gov. Read them yourself.
- Clinical trialEarly-phase Biomarker-based Trial of NPC-1 for Alzheimer's Disease PathologyClinicalTrials.gov ↗PHASE2 · 40 participants · Recruiting
Evidence surfaced via Semantic Scholar (Allen Institute for AI) and ClinicalTrials.gov. Ranked by study type and citation weight, not cherry-picked.
Problems people have reported.
Read this carefully. These are 158 voluntary, unverified reactions reported to the FDA (openFDA). The number mostly reflects how popular Ipriflavone is, not how risky it is. A report is not proof Ipriflavone caused anything. It is a signal of what to watch for, nothing more.
Source: openFDA adverse-event reports. Voluntary reporting, not an incidence rate.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.