Iām more and more interested in intermittent hypoxia therapy.
This paper by Matt Kaeberlein showed that it doubles lifespan in worms: Intermittent hypoxia therapy engages multiple longevity pathways to double lifespan in C.elegans 2022
The protective effects ischemic preconditioning (IPC) in mammalian systems requires the activity of G-protein coupled receptors, and inhibition of Gi/o with pertussis toxin can abrogate this protection(31). While IPC has been studied for decades, and the use of various IHT regimes to improve athletic performance equally well established(32), the clinical use of hypoxia in western medicine has been relatively limited(33). However, recent work shows that exposure to continuous hypoxia can rescue mitochondrial dysfunction in a mouse model of the mitochondrial disease Leigh syndrome, while an IHT regime failed to show a similar results(34, 35). Mitochondria are the primary consumers of molecular oxygen in the cell and mitochondrial dysfunction is one of the key hallmarks of aging(36). The role of oxygen in the aging process, primarily as a putative source of damaging ROS has been hypothesized for decades, however low oxygen therapies have shown limited results in increasing longevity(37). Our results suggest that organismal responses to low oxygen are complex, and that sensory or reproductive signals triggered by acute hypoxia exposure, rather than decreased total lifetime oxygen levels, can trigger endogenous protective pathways to dramatically increase lifespan in wildtype animals. Further studies are warranted to determine whether the effects of IHT on longevity are conserved in mammals with the potential to promote healthspan and lifespan in humans.
Hypoxia is currently being studied in an RCT for Parkinsonās disease: Parkinson's disease - #371 by adssx
Thereās the protocol: Randomized controlled trial of intermittent hypoxia in Parkinsonās disease: study rationale and protocol 2024
They showed safety in a phase 1 trial. The researcher told me: āOur the main manuscript from our first study is currently in revision, and we are writing up the manuscript for the second study as all lab results have just come in.ā
If successful, it might explain some mysteries of Parkinsonās disease: why are exercise, smoking, and altitude protective? 
Iāll give a try to intermittent hypoxia, trying to reproduce the protocol in the PD study:
45 min of normobaric intermittent hypoxia (fraction of inspired oxygen 0.16 for 5 min interspersed with 5 min normoxia), 3 times a week for 4 weeks
A commercially available hypoxic generator (b-Cat ALT-120, B-cat High Altitude, Tiel, the Netherlands) is used, which is similar to devices regularly used in hypoxic training studies
the device automatically titrates the correct fraction of inspired oxygen (FIO2) of 0.16 in a closed feedback loop with an FIO2 sensor
I also found this machine but canāt find its price: https://www.cell-oxy.com/