The aim of the study is to investigate whether inhalation treatment with high-sulfide waters from some spas (referred to as "thermal waters"), performed for 12 consecutive days, is able to change circulating H2S levels and alter bone metabolism. Identifying a clear correlation between circulating levels of H2S and sulfur water administration, as well as a potential anabolic effect on bone, would set the stage for new studies that could have important clinical implications for promoting health and preventing osteoporosis

Inclusion Criteria:

• post-menopausal women with a diagnosis of osteopenia

Exclusion Criteria:

• concurrent muscoloskeletal conditions or chronic pharmacological treatment interfering with bone metabolism

post-menopausal women, a condition which is associated with the development of osteoporosis