If a mid 30's guy who just wanted enough extra T to get him to be at mid 20's level, how much would he take of enanthate or nandrolone? When does an external amount start to bring down your body's natural T? Thanks in advance for anyone's suggestions.
First off, nandrolone will not increase your testosterone levels.
The T level of a man in his 30's compared to a man in his 20's is going to be different in different individuals. Some thirty year olds will need more T than other 30 year olds to put them in 'high-normal' range.
I don't have an answer to your question but I would recommend getting your hormone levels tested before putting anything in to your body.
Your question about suppression of natural T can be answered with a google search.
There is not an answer Bonez - thats why. As you stated, it varies.
Agreed, steroids other than T will not increase T levels, but decrease them - however they are still AAS like T (and derived from) so will still exert similar effects to T itself - with variances in some areas and similarities in others, depending on the compound.