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Tempol
A free-radical scavenger painted on the scalp before radiotherapy kept hair in guinea pigs and, in a small phase I trial, protected the hair of some brain-radiotherapy patients, but it never became a product.
What it is
An experimental stable free radical studied as a radioprotector. It is not approved anywhere for hair.
How it works
It soaks up radiation-generated free radicals in follicle tissue before they damage DNA.
What the studies show
- In guinea pigs given eight daily radiation doses, topical Tempol (70 mg/mL) kept hair density at about 75% versus about 25% in controls at weeks 9-13. A related nitroxide, Tempo, kept about 90% versus 12%. Cuscela 1996
- In a phase I trial of 12 patients (11 treated) having whole-brain radiotherapy, the solution was applied 15 minutes before each of 10 sessions and washed off afterwards. It was well tolerated (mild low blood sugar in 3, mild skin reactions). Hair was kept only where the solution pooled in the first four patients, then across the whole scalp in 3 of the last 5 evaluable patients after gauze wrapping. Open label, no control. Metz 2004
- The authors planned a phase II gel study; we found no results.
How it's used in studies
70 mg/mL solution applied to the scalp before each radiation dose and washed off after. Not for self-use.
Side effects and safety
Mild low blood sugar, skin redness and tingling in the phase I trial. Whether it could also protect tumours was not assessed here.
Bottom line
One small uncontrolled human trial. Interesting as a rare compound that shields follicles from radiation, but unavailable and unproven. Discuss with a doctor.
Fun facts
- A free-radical scavenger painted on scalps before brain radiation kept hair across the whole scalp in 3 of 5 evaluable patients once the solution was held against the skin. Metz 2004
Studies 2
Cuscela D et al. Protection from radiation-induced alopecia with topical application of nitroxides: fractionated studies. Cancer J Sci Am. 1996
Tested: topical Tempol 70 mg/mL
Result: Hair density about 75% vs about 25% in controls at weeks 9-13; Tempo about 90% vs 12%.
Read the study ↗Metz JM et al. A phase I study of topical Tempol for the prevention of alopecia induced by whole brain radiotherapy. Clin Cancer Res. 2004
Tested: topical Tempol 70 mg/mL before each of 10 fractions
Result: Well tolerated; hair retained where solution pooled, then across the whole scalp in 3 of the last 5 evaluable patients; open label, no control.
Read the study ↗Related
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