My update:
It is now roughly 4 weeks past my last IV. I tried to log my symptoms, but live life normally otherwise.
I have noticed that in about a week after the last IV, my ear pressure started to go down. Before I would get ear pressure in response to sound exposure, but not anymore, or not to the same extent. I haven't tried exposing myself to continuous 85 dB noise, obviously, but I do not get ear pressure anymore after going to a restaurant (without plugs). I am also using headphones daily with no downsides.
My tinnitus, however, has stayed roughly the same. I think one or two sounds have disappeared (I have very many), and maybe the reactivity has lessened, but that is it. The baseline is pretty much the same or maybe slightly lower.
My hearing is also the same, no improvement in high frequency clarity.
My thoughts on why it was not as effective as I had hoped:
They administered 3 IVs, each had 7.5 ml secretome, with about 9*10^8 exosomes/ml. This is around 20 billion exosomes from the 3 doses combined, so about 0.33 billion per kilogram of body mass. However, in
this paper they used about 3 orders of magnitude more per kilogram in mice, according to my calculations. The drug dose per kg needs to be adjusted when going from animal models to humans (
a factor of 8-12 less for humans, but it does depend on the specific drug, obviously), so basically there was a factor of 100 difference between the dose that I received and what may have been more effective.
In addition, perhaps adipose tissue stem cells are not as potent as umbilical cord stem cells used in the paper above.
The verdict: it is not worth 20,000 EUR for tinnitus or hearing loss. My results are pretty inconclusive. As this is not a study (sample size N=1 and no controls, lol), I cannot say that my sensitivity improvement was due to the secretome. However, the clinic seemed very professional (no fake body scan BS you see in,
ahem, other clinics) and they do see improvement in patients with neurological conditions, at least according to them.