ITPP (Myo-Inositol Trispyrophosphate)
ITPP is an experimental allosteric effector of haemoglobin that shifts the oxygen dissociation curve, making haemoglobin release oxygen to tissues more readily. Studied preclinically for hypoxic tumours and heart failure, it has never been approved for humans, yet the term 'Oxymo' circulated in doping contexts. WADA prohibits efaproxiral and agents affecting oxygen delivery.
01 Overview
Myo-inositol trispyrophosphate (ITPP) penetrates red cells and acts like an allosteric effector similar to 2,3-BPG, right-shifting the oxyhaemoglobin dissociation curve so that more oxygen is offloaded to tissues at a given oxygen tension. Animal work explored it for tumour hypoxia and exercise capacity in heart failure models.\n\nHuman data are essentially absent; safety, dosing and long-term effects are uncharacterised. Concern about its potential as a doping agent (sometimes marketed under names like 'Oxymo') led to anti-doping scrutiny even though it is not an approved drug. Any use is experimental and unmonitored, with unknown risks.
02 Mechanism
Enters erythrocytes and binds haemoglobin as an allosteric effector, decreasing haemoglobin's oxygen affinity and right-shifting the dissociation curve so more oxygen is released to peripheral tissues.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Experimental (animal/early trial) | 1–3 g/m2 | IV | Doses extrapolated from experimental oncology settings; no established human regimen |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Enhanced tissue oxygen releaseIn animal models it increases oxygen offloading to tissues, improving exercise tolerance in heart-failure models. | Right-shifted O2 curve | Preclinical | |
| Improved exercise capacity (animal models)Rodent studies reported improved exercise capacity, but this has not been demonstrated in controlled human trials. | Uncertain in humans | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Unknown human safety profileNo adequate human safety data; effects on electrolytes, kidney and long-term outcomes are unknown. | Moderate | Uncharacterised | Preclinical | |
| Potential impaired oxygen loading in lungsExcessive right-shift could theoretically impair oxygen uptake in the lungs at altitude or during intense effort. | Moderate | Theoretical | Preclinical |