l carnitine help build muscle Carnitine: the claims and why it may not work L-Carnitine for Cutting vs Bulking:

The fitting routine did not always fit all the components in all the spectra, which is reflected by the number of participants for a given metabolite in Table 2

Decline with age Reduction in NAD+ levels between 20 and 60 years of age, leading to mitochondrial dysfunction and sirtuin deficiency

That means they built a little muscle at the same time

Blood 115 , 804814 (2010)

Real-world use of finerenone in patients with chronic kidney disease and type 2 diabetes based on large-scale clinical studies: FIDELIO-DKD and FIGARO-DKD

ROS can cause breaks in the DNA strands within sperm, leading to single-strand and double-strand breaks