In
this interview (at around 29 minutes), Scott Scherr, MD, who is one of the leading HBOT researchers and practitioners in the US, talks about Shai Efrati's protocol in Israel. According to Dr. Scherr, the protocol involves 60 sessions of 2 ATA pressure, where they take off the mask after 20 minutes and leave it off for 5 minutes and repeat. Each session is 90 minutes at pressure, which corresponds to 90 "pressure minutes" per session. I define a "pressure minute" as one minute at 2 atmosphere's pressure, equivalent of being at 10 meters (33 ft.) depth in water. The entire protocol gives a user 90 "pressure hours"
For those who have a 1.5 ATA system, they get only 0.5 "pressure minutes" per minute in the pressurised chamber. If we do a session of 60 minutes at 1.5 ATA (plus 10-15 minutes to reach full pressurisation), the sessions gives us 0.5 "presssure hours". So in order to get the equivalent "presssure time" as Dr. Efrati's protocol, we need to do 180 sessions at 60 minutes of pressure. Alternatively, we can increase the duration of each session to do 90 sessions with 2 hours at pressure or 127 sessions of 1.5 hours at pressure.
As I understand it, it's not necessary to get the same pressure exposure as Dr. Efrati to get some the benefits from HBOT. Dr. Scherr says that the "minium viable product" approach of estimating the minimum number of treatments to get sustainable benefits is 30 sessions. However, that does depend on age, general health conditions, diet, etc. For most people looking to get reverse ageing benefits Dr. Scherr refers to a study that has found that maximum senescent cell downregulation and telomere length contribution takes place at 30 sessions. He doesn't specify at what pressure and duration but as I understand it, it is implied that it's a similar setup as Dr. Efrati from Israel.
If these benefits follow a normal distribution, then half of the total benefits take place before the peak value and the remaining half take place after. So if you stop at the number of sessions when you reach peak effect, it means that you're only getting half the potential benefit.
All in all, that's a pretty lengthy protocol...