ITPP

Myo-inositol trispyrophosphate

ITPP (Myo-inositol trispyrophosphate) is a metabolic & fat loss research compound. Allosteric effector of hemoglobin — shifts the oxygen-dissociation curve so red cells release more O2 to tissue; endurance/hypoxia angle.

How ITPP works

Allosteric effector of hemoglobin — shifts the oxygen-dissociation curve so red cells release more O2 to tissue; endurance/hypoxia angle.

Proposed benefits

Researched for fat oxidation, appetite and energy regulation, insulin sensitivity and endurance capacity.

Where to get ITPP

The evidence for ITPP

Graded by what exists behind each claim.

Human clinical evidence

• No human trials: development stopped at preclinical, so the ceiling on any claim here is a rodent model — and these transfer poorly.

📊 Correlative data

• Known primarily through equine doping — it was detected in racehorses and prompted regulatory action in several jurisdictions, and it is on the WADA prohibited list for human sport.
• Human research-market use is limited and the reported experience is unreliable, because the claimed effect — altered oxygen offloading — is not something you can perceive directly.
• Beyond that the record is self-reported: community dosing logs are real information about tolerability and almost none about efficacy.

🧪 How the mechanism reads

• An allosteric effector of hemoglobin. It enters red cells and binds hemoglobin at the 2,3-BPG site, shifting the oxygen dissociation curve rightward — meaning hemoglobin holds oxygen less tightly and releases more of it to tissue at any given partial pressure.
• This is the opposite strategy to EPO: rather than carrying more oxygen, deliver more of what is already carried. In tumor models it was studied for reducing hypoxia, which is where the original research interest came from.
• A rightward shift has a hard ceiling and a real cost. Shifted too far, hemoglobin fails to load properly in the lungs — the same curve that improves unloading impairs uptake, and nobody has established where that crossover sits in humans.

Why an empty tier is not a verdict → · What community dosing logs are worth →

How to read these tiers: they say how much human evidence exists, not how well something works — and ✗ flags harm, never a disappointing trial. How the evidence tiers work →

What ITPP actually does

ITPP is the only compound in this cohort whose mechanism is a piece of physical chemistry rather than a signaling pathway, and that makes it unusually easy to test and unusually easy to get wrong. Hemoglobin binds oxygen with an affinity that is not fixed — it is set by allosteric effectors sitting in the central cavity between the beta chains. The natural one is 2,3-diphosphoglycerate, a polyanion made by the red cell itself; it stabilizes the low-affinity tense state, so the more of it there is, the more readily hemoglobin lets oxygen go. myo-Inositol trispyrophosphate is a synthetic, more strongly charged version of exactly that.

Fylaktakidou 2005 synthesized nine ITPP salts, showed they cross the red blood cell plasma membrane, and reported the consequence directly: the oxyhemoglobin dissociation curves were significantly shifted towards higher values of oxygen partial pressure. That is a right shift — a higher P50, the oxygen tension at which hemoglobin is half saturated — and it means the same hemoglobin gives up more oxygen at the same tissue oxygen tension. Nothing is added to the blood. The release characteristics of what is already there are changed.

The entry route is a named transporter, and it is why the effect is red-cell selective. Duarte 2010 showed ITPP uptake is mediated by band 3 — the anion exchanger that is the most abundant protein in the red cell membrane — and confirmed it by blockade: DIDS and NAP-taurine inhibited the ITPP-induced shift of the oxygen-hemoglobin equilibrium. The same paper reports a maximum intracellular concentration of 5.5 × 10⁻³ M and a dissociation constant from red cell ghosts of 1.72 × 10⁻⁵ M, and describes the uptake as highly tissue-selective towards RBCs. A polyanion of this charge cannot diffuse through a lipid bilayer in either direction; band 3 is the door, and red cells are the only cells with enough of it to matter. That single fact is the whole selectivity argument for this molecule.

And here is the second-order consequence, which is the interesting half and the one that cuts both ways. If tissue oxygen tension rises, the oxygen sensor stops firing. Kieda 2006 put human microvascular endothelial cells under hypoxia with human red cells loaded with ITPP, and the elevated hypoxia-inducible factor 1α and VEGF were dramatically reduced or even suppressed; the treated endothelial cells did not align into vessel-like structures. So ITPP is not just an oxygen-delivery agent — it is an anti-angiogenic one, by the most direct route imaginable: it removes the hypoxia that drives angiogenesis. That is why the compound’s serious research literature is oncology, not sport.

Cell, rodent, human — and where it stops

Step one, in a tube. Nine salts synthesized, membrane permeation demonstrated, oxyhemoglobin dissociation curve shifted right Fylaktakidou 2005. Pure chemistry, no cells needed.

Step two, in human cells. Human microvascular endothelial cells under hypoxia, with human red cells pre-loaded with ITPP: HIF-1α and VEGF suppressed, tube formation abolished Kieda 2006. Note the design — the ITPP was loaded into red cells first, which is the route the chemistry demands and not a route any person has.

Step three, the transporter identified. Band 3 mediates uptake; DIDS and NAP-taurine block the effect; intracellular concentrations reach 5.5 mM Duarte 2010. This is the step that turns a physical-chemistry observation into a pharmacology.

Step four, whole animals, and the effect size is large. Biolo 2009 gave ITPP to normal mice and to transgenic mice with severe heart failure, by intraperitoneal injection at 0.5–3 g/kg and by oral administration in drinking water. Maximal exercise capacity rose by 57 ± 13% (P = 0.002) in normal mice and 63 ± 7% (P = 0.005) in the failing ones, with a maximal 31% increase in P50. Critically, it had no effect on myocardial contractility in isolated cardiac myocytes — so the improvement was oxygen delivery, not inotropy. That is a clean, well-controlled result.

Step five, in humans: nothing. There is no human trial, no human pharmacokinetic study, no published human P50 measurement on ITPP, and no human safety dataset at any dose. The one human-adjacent literature is analytical: Wong 2012 developed a hydrophilic interaction chromatography–tandem mass spectrometry assay for equine urine and plasma, detecting ITPP at low parts per billion, and stated the reason plainly — ITPP is an ideal candidate as a doping agent and there was speculation in the horseracing industry that covert use is already widespread, with no reported detection method. The first serious effort to measure this compound in a living body was made in order to catch people.

The obstacle, stated exactly, and it is arithmetic. The rodent effect came from 0.5 to 3 g/kg Biolo 2009. Convert by the standard body-surface-area factors (mouse 3, human 37) and the human-equivalent dose is roughly 40 to 240 mg/kg — about 2.8 to 17 grams for a 70 kg adult. Set that against the 500–2000 mg this site records and the vault dose sits at or below the bottom of the scaled animal range, by a factor of roughly one and a half to seventeen. That is a calculation, offered as one. What it means is that the honest description of a 1 g dose is not “a conservative version of a proven effect” but “an exposure below anything that has produced an effect in any species.”

ITPP pharmacokinetics — how much of it actually gets in

Route: this is where the vault card and the chemistry disagree, and the chemistry wins. The published animal work used intraperitoneal injection and oral administration in drinking water Biolo 2009; the cell work loaded red cells ex vivo Kieda 2006. There is no published subcutaneous pharmacokinetic study of ITPP in any species, and injecting gram quantities of a polyanionic salt subcutaneously is not a route the literature supports.

The oral barrier, and it is a real one. ITPP is a small, heavily charged polyanion — that is the entire point of the molecule, because charge is what lets it grip the cationic pocket in hemoglobin. The same charge is what stops it crossing a lipid membrane by diffusion, which is why entry into a red cell requires band 3 Duarte 2010. An enterocyte membrane presents the identical problem with far less band 3, so oral bioavailability should be poor on first principles. The mice drank it for weeks; a sustained low-level exposure is a very different thing from a single capsule, and no oral bioavailability figure for ITPP has been published in any species.

What degrades it: probably nothing — and that changes how to think about half-life. There is no published metabolite, no cytochrome assignment and no hepatic clearance fraction. A polyanion of this size is a classic candidate for glomerular filtration with negligible tubular reabsorption, which predicts rapid renal clearance and a short plasma half-life. But plasma is the wrong compartment to be thinking about. The pharmacologically active pool is inside the red cell, at up to 5.5 mM Duarte 2010, behind a membrane the molecule cannot re-cross without band 3. So the duration of the P50 shift is set by red-cell efflux and by red-cell turnover — a population with a lifespan measured in weeks to months — not by how fast the kidney clears plasma. A short plasma half-life and a long-lasting effect are entirely compatible here, and nobody has measured either one in a person.

The one measurement that has actually been made in a living body. Wong 2012 detected ITPP at low parts per billion in equine plasma and urine by solid-phase extraction and HILIC tandem mass spectrometry. That establishes two things: the compound does reach systemic circulation after administration in a large mammal, and it is detectable — which matters to anyone subject to testing, because the assay exists specifically because regulators expected to find it.

What would have to be true, and how you would know it was not

Four predictions. The first two would show it is working, and the third and fourth are the ones that argue against using it the way people intend to.

1. If it works, hematocrit should go DOWN, not up — and this is the most counterintuitive falsification test in the cohort. Erythropoiesis is driven by renal hypoxia sensing. A right-shifted dissociation curve delivers more oxygen per gram of hemoglobin, so the kidney sees less hypoxia, erythropoietin falls, and red cell production should follow. Run a CBC and a reticulocyte count at baseline, 4 weeks and 8 weeks. A falling reticulocyte count with a stable or slightly falling hematocrit is the signature of the mechanism operating. A rising hematocrit means either the compound is doing nothing or something else changed — it is not what this mechanism predicts, and anyone selling ITPP as a blood-builder has the physiology backwards.

2. The performance read-out has to be a ramp test, not a feeling. The mouse effect was 57–63% higher maximal exercise capacity Biolo 2009. An effect of even a fraction of that size is measurable with a VO2 ramp or a fixed-workload time to exhaustion, repeated three times before starting to establish a coefficient of variation. If a properly baselined ramp test shows nothing at 1–2 g, the most likely reason is exposure — see the arithmetic above — and the correct response is to stop, not to escalate a compound with no human safety data.

3. The prediction that cuts against most intended use: the effect should be near zero in a healthy person at sea level. Shifting the dissociation curve only helps where oxygen delivery is the limiting step. In the mouse experiment the largest gain was in animals with severe heart failure Biolo 2009 — delivery-limited by definition. A healthy trained adult at sea level is usually limited by cardiac output and mitochondrial capacity, not by hemoglobin unloading, and a right shift also makes loading in the lung slightly harder. So the mechanism predicts a bigger effect at altitude, or in anemia, or in heart failure, and a small one where most people would use it. Test it by repeating the same ramp protocol at altitude and at sea level.

4. The prediction that should worry an athlete: training adaptation may be blunted. Kieda 2006 showed ITPP-loaded red cells suppressed HIF-1α and VEGF and abolished endothelial tube formation. Exercise-induced capillary growth runs through that same hypoxia–HIF–VEGF axis. So the mechanistic prediction, never tested in any species, is that chronic ITPP reduces the angiogenic response to training — better oxygen delivery today at the cost of less capillary density later. The measurable version is a training block run with and without it, comparing the change in VO2 across a matched eight-week program rather than the acute test.

What nobody has tested yet

No human has ever had a P50 measured on ITPP. This is the single most valuable missing number and it is not a hard measurement — a blood gas analyzer with a tonometry attachment produces an oxygen dissociation curve from a few milliliters of blood. Every claim on this page rests on a 31% P50 increase in a mouse Biolo 2009. One person, one dose, two blood draws, and the central question of whether the compound does anything at all in a human would be settled.

Nobody knows how long the effect lasts after a single dose. The pharmacology sits inside a cell the molecule cannot easily leave Duarte 2010, so the effect should outlast the plasma concentration by a long way — possibly by the lifespan of the red cell population. Nobody has run a time course of the P50 shift after one dose in any species, which means the correct dosing interval is unknown even in mice. Daily dosing of a compound that accumulates in a cell with a months-long turnover is a plausible route to overshoot, and nothing in the literature bounds it.

Nobody has looked at the red cell itself. Loading an erythrocyte to 5.5 mM with a polyanion, through the transporter that also anchors the membrane cytoskeleton Duarte 2010, is a substantial ionic and osmotic perturbation. Osmotic fragility, deformability and hemolysis at those loadings have not been published, and they are standard hematology bench tests. Red cell deformability in particular is what lets an erythrocyte pass a capillary narrower than itself — the very step that oxygen delivery depends on.

And nobody has tested the anti-angiogenic effect against the performance effect in the same animal. The oncology rationale and the endurance rationale are the same mechanism read in opposite directions Kieda 2006 Biolo 2009, and no study has measured muscle capillary density and exercise capacity together over a training period. That experiment would tell you whether ITPP is an ergogenic aid with an oncology side-effect or an anti-angiogenic drug with an ergogenic side-effect, and at present nobody can say which.

ITPP — its own safety story, not its class's

Start with the plain statement: there is no human safety data for this compound at any dose. No trial, no case series, no published toxicology in a person, no regulatory dossier anywhere. Everything below is either an animal observation or a mechanistic inference, and it is labeled as such, because the alternative on this page would be to imply a safety record that does not exist.

The risk that follows directly from the mechanism is the angiogenesis one, and it runs in both directions. Suppressing HIF-1α and VEGF Kieda 2006 is the basis of the oncology interest, and the same suppression is not obviously benign in someone who is well. HIF-1α signaling is required for normal wound healing, for the vascular response to ischemia and for exercise-induced capillary growth. Nobody has measured wound healing, or any angiogenesis-dependent process, in an animal or a person taking ITPP chronically.

The red cell is the target organ, and it has never been examined as one. The compound is concentrated to 5.5 mM inside the erythrocyte via band 3 Duarte 2010 — a protein that is simultaneously the cell’s anion exchanger and part of its structural anchor. Nothing in the published record reports osmotic fragility, hemolysis, or membrane deformability at therapeutic loadings. For a compound whose entire purpose is to modify the red cell, that is the specific gap that matters, and it is not covered by any class-level safety statement.

Dose scale, and why the numbers should be read carefully. The animal work used 0.5 to 3 grams per kilogram Biolo 2009 — gram-per-kilogram dosing, not milligram-per-kilogram. Salt and osmotic load at that scale is a genuine consideration in its own right, separate from any pharmacology, and the route matters: the published routes are intraperitoneal and oral in drinking water, not subcutaneous. Nobody has published what happens when grams of a polyanionic salt are deposited under the skin.

And the risk that is not medical. Wong 2012 built a detection assay for equine plasma and urine because ITPP is an ideal candidate as a doping agent and covert use was already suspected to be widespread in horseracing. The compound is detectable at low parts per billion. Anyone in a tested sport should read that as settled: the analytical method exists and it works at concentrations far below a pharmacologically active one.

Sources read for this page

• Fylaktakidou KC, Lehn JM, Greferath R, Nicolau C. Inositol tripyrophosphate: a new membrane permeant allosteric effector of haemoglobin.. Bioorg Med Chem Lett 2005 · PMID 15745806
• Duarte CD, Greferath R, Nicolau C, Lehn JM. myo-Inositol trispyrophosphate: a novel allosteric effector of hemoglobin with high permeation selectivity across the red blood cell plasma membrane.. Chembiochem 2010 · PMID 21086482
• Biolo A, Greferath R, Siwik DA, Qin F, Valsky E, Fylaktakidou KC, Pothukanuri S, Duarte CD, Schwarz RP, Lehn JM, Nicolau C, Colucci WS. Enhanced exercise capacity in mice with severe heart failure treated with an allosteric effector of hemoglobin, myo-inositol trispyrophosphate.. Proc Natl Acad Sci U S A 2009 · PMID 19204295
• Kieda C, Greferath R, Crola da Silva C, Fylaktakidou KC, Lehn JM, Nicolau C. Suppression of hypoxia-induced HIF-1alpha and of angiogenesis in endothelial cells by myo-inositol trispyrophosphate-treated erythrocytes.. Proc Natl Acad Sci U S A 2006 · PMID 17028170
• Wong AS, Ho EN, Wan TS. Detection of myo-inositol trispyrophosphate in equine urine and plasma by hydrophillic interaction chromatography-tandem mass spectrometry.. Drug Test Anal 2012 · PMID 22359395

ITPP — safety, predicted from mechanism

ITPP — interference & stacking

Bloodwork to run alongside ITPP

Baseline first, then again at 8–12 weeks.

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ITPP — frequently asked questions

ITPP inside a finished plan

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What ITPP is used for

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