Hi, Meieli, I'm a doctor and have been performing platelet rich plasma injections (the scientific name for stimulated serum) for orthopedic/musculoskeletal conditions for almost 5 years with excellent results. The way it works: At the time of injury platelets congregate at the site of the injury to create a blood clot (everyone knows this) but platelets also release proteins that are directly responsible for tissue healing and regeneration - so basically injecting platelets into an injury that never fully healed such as a tear, chronic tendonitis, (even arthritis), tricks your body into thinking that it has undergone a new injury (but it has not) and this launches your body's natural healing mechanisms to grow new, healthy, collagen. About a year ago I learned of the cosmetic applications so I tried it on my girlfriend (of course) - to date I've performed this on about 18 women and 2 men and they have all been THRILLED. The 2 main applications are for filling folds and for rejuvenating aging skin (can be done anywhere on body such as face including eyelids or hands). Additionally, even though I've only been doing this for a year, so far the results are lasting and in fact you continue to notice improvement many months out. Anyway, hope this helps Dr Harry Adelson