The goal of this prospective observational study is to evaluate whether injections of stem cells derived from the patient's own fat tissue (adipose tissue) can improve erectile function in men aged 30 to 75 who have erectile dysfunction (ED) and have not responded well to standard treatments like PDE-5 inhibitors (e.g., Viagra). The main questions the study aims to answer are: Will the stem cell injections improve erectile function, as measured by the International Index of Erectile Function (IIEF) score? Are there any changes in blood flow to the penis, which will be measured using a Doppler ultrasound? Participants will: Receive injections of their own stem cells (obtained from a biopsy of fat) directly into the penis. Undergo assessments to check erectile function before and after treatment. Have follow-up visits at 3, 6, 9, and 12 months to monitor long-term effects. The study will also look for any possible side effects or complications and evaluate biological markers in the penis that may indicate the effectiveness of the treatment. Participants will be recruited from clinic where they are already receiving care for ED. To take part, they must be in good overall health, with no severe heart disease, uncontrolled diabetes, cancer, or other conditions that could make stem cell therapy unsafe for them.