And now for the actual answer.
Tren, mg for mg, is much safer than winstrol.
There is very little evidence supporting the notion that trenbelone is even moderately toxic. True, there are anecdotal reports of kidney stress, but logic simply does not place trenbelone at the root of the issue there. A more likely culprit is oxidized methylcellulose, or even excessive BA or BB.
In any event, trenbelone exerts minimal stress on the liver (if any), and has a less profound impact on HDL/LDL ratios.
Moreover, tren does not dehydrate the body as dramatically as winstrol, nor is the hematocrit level impacted as severely.
Winstrol is a very harsh drug, contrary to popular belief.
Those who have run both and gotten regular bloodwork will corroborate this position, with very few exceptions.