Polyamines are essential molecules of highly proliferative tissues, where they play a fundamental role in cellular metabolism like RNA and DNA synthesis, control and initiation of translation, growth and cell proliferation, mediators of most of all hormones and growth factors. Many studies have already shown that polyamines, and spermidine in particular, are strongly related to the regular functioning of hair follicle in animals, and that the modification of their synthesis results in significant alterations in the growth and structure of hair fibers. We made a long-term double blind clinical trial placebo controlled and an examination of HF ex vivo by confocal microscopy to understand if the addition of a specific amount of spermidine (as a nutritional supplement) could be efficacy to stop hair loss in chronic telogen effluvium in women underwent hair loss. Our results show the efficacy of this treatment, and we hypothesize the possible mechanism of action of spermidine in hair follicle.