31st March 2026 Newsletter
Hi guys. This is the fifteenth newsletter from the Rejuvenation Science Institute (ICR). In these newsletters, we will tell you what we've done, since the last newsletter, to accelerate the development of rejuvenation science.
We have the first partial results of grip strength in Katcher’s reproduction experiment
Image for illustrative purposes only
The ICR is reproducing the seminal experiment of Harold Katcher, in which he epigenetically rejuvenated old rats by 67%. On March 17th (two weeks ago) it was injected the first dose of the treatment in the old rats. The dose was divided in four injections, which were injected on days 1, 3, 5 and 7 of the experiment. The control group received a sham injection. The grip strength of the animals was assessed 5 days before the first injection. Then, the first grip strength test post-treatment was carried out 5 days after the last injection, which means that 16 days passed between the two grip strength tests.
On average, the grip strength of the treated rats increased by 44% in comparison with the first test. However, the control rats also showed an increase in grip strength, by 32%, which means there are other factors affecting the general increase of the grip strength. One probable factor is the training of the animals, which are more and more skilled in holding the bars in the grip strength test. This effect should be less pronounced in the next grip strength test, schedulled to be carried out next week. Another possible influence, in the case of the control rats, is that the sham PBS injection could dilute their plasma, diluting also the old age signaling. However, this effect is less potent and durable than the injection of young age signaling. So, this effect should also be less influent in the next grip strength test. In any case, we (and you) will have more information about that after the next grip strength tests.
Another important partial result is that the treated rats appear to be healthy. There are no signs that show that the injections have deleterious effects on them. Also, we have collected blood from the animals before the first injection and will collect again in several points of the experiment to check their blood markers, but these results will be available later.
The first memory test will be carried out between the 13th and the 21st of April, so in the next newsletter, we will probably have already these preliminary results. So, after 6 years waiting for answers, the first answers are starting to appear. Stay tuned!
This is a collective effort
This experiment is a collective effort to reproduce Harold Katcher's seminal study, in which the ICR relies on the contribution of those interested in the realization of the experiment. Thus, if you know someone who might be interested in the content of this newsletter, you can forward it to them. Also, if you are not yet a financial contributor of the ICR, we invite you to become one by clicking on this link.
So that's it. We're carrying on, and we won't rest until we've implemented rejuvenation in human beings. See you next time!