Not true. You can run deca alone with no issues. It’s the deca test combo that causes the issues.
When I got back into the scene I started a cycle with deca and dbol as that was a pretty typical cycle we would run in the past. I would have been around 40 ish and had zero issues with ED. It wasn’t until someone online told me I had to get test in every cycle did things go a little off.
Deca is really an amazing AAS but it’s got a bad rap.
"Test needs to be your cycle base" wasn't really a thing until internet forums in the early 2000s lol.
I have an online interview with Robbie Robinson where they were talking about Steroids. When he was asked about testosterone his response was literally "You know, I dont want a speak about testosterone. I've never used it, and nobody else was using it either, so I just can't speak to it from any sort of personal experience."
Lee Priest has talked about how the one time he tried a cycle with test in it he absolutely hated the test side effects.
Think of your endocrine system as having a "lock" on your androgenic functions. Testosterone, Nandrolone, Dianabol, Boldenone are all keys that will fit that lock. Your choice of which key you use will depend on which side effects you want to avoid.
Example, I personally would never use EQ as a base, as boldenone has a tendency to cause me erectile dysfunction even when all of my sex hormones are in perfect range.
I dont like test as a base either very much (though I am currently using it) because I am very sensitive to the side effects (I need to abuse the fuck out of AIs even at 250mg/wk). I get acne, oily skin, water retention, and I become aware of my prostate at all times.
I can use 600, 900, even 1200 mg of Nandrolone without even needing an AI, holding no bloat, no acne. At 600 I need a little dbol for estrogen, which, believe it or not, is a lot more gentle than testosterone when used in this manner.