One extraordinary presentation at "Ending Age-Related Diseases 2022 " was by Greg Fahy, on past and new clinical trials to regenerate the thymus - a gland which sadly shrinks in age, and is a key player in the immune system.
The initial human clinical trial was named "TRIIM", at Stanford (2015-17), with notable results.
A new trial is in progress: "TRIIM-X".
From abstract of 2019 paper ("Reversal of epigenetic aging and immunosenescent trends in humans"): "Using a protocol intended to regenerate the thymus, we observed protective immunological changes, improved risk indices for many age-related diseases, and a mean epigenetic age approximately 1.5 years less than baseline after 1 year of treatment (−2.5-year change compared to no treatment at the end of the study)" https://onlinelibrary.wiley.com/doi/full/10.1111/acel.13028
What protocol did they use? Greg Fahy explained at length, in a very informative post-talk session, that a key ingredient is Growth Hormones ("in use clinically since 1996; it grows the thymus in every species which it has been tried on".) HOWEVER, Growth hormones possess a darker side: being "diabeto-genic"...
To counteract that, they added 2 "antidotes" to the side effects of Growth Hormones, namely Metformin (anti-diabetic) and DHEA (an adrenal steroid hormone that the body naturally produces; in high levels in young people, who have plenty of growth hormones with no ill effects.)
For more information about the trials, including for anyone wanting to enroll in their 2nd-generation clinical trials: https://interveneimmune.com/ (a Los Angeles-based company)
Details on the new trials: https://clinicaltrials.gov/ct2/show/NCT04375657