There is a lot more nuance to endocrinology and neuroscience than just testosterone=good, cortisol=bad, inflammation=bad and even though a lot of biohacking discourse is about increase/decreasing those things, most people wouldn't actually benefit from that, even if they think they do.

The problem

Many brands and influencers promote supplements because they lower cortisol, increase dopamine, increase testosterone etc. which gives people the impression that these things are the root of their depression, low productivity, anxiety, adhd, lethargy, sexual dysfunction and other problems they are facing.

This leads people to chase the wrong goal. To buy a bunch of "cortisol-blocker" supplements to improve their productivity when (as Ill get into later) that is likely doing more harm than good.

Testosterone

Low testosterone is a very rare condition among men who aren't obese or old. Only around 2.5% of non-obese men between 19 and 40 years of age have a testosterone level below 350ng/dl. That would still be considered normal clinically. Depending on where the test is taken, below 300 or below 200 is usually considered to be hypogonadism. Just because influencers always share their blood tests which are between 900 and 1200, that doesn't mean that you have low testosterone because you are in the 500s, that's still completely normal and you don't need trt. Why do all of these people online talk about how they changed their lifestyle to increase their testosterone and then they felt better? Because sleeping more, losing weight and exercising makes you feel better, independent of your testosterone levels. And partly because of the placebo effect. Yes, testosterone can make you feel more confident but it can also make you more anxious or irritable. It will lead to earlier hair loss, worse cholesterol levels and higher estrogen which could lead to acne, gyno, mood changes and so on. The effects of slightly higher testosterone aren't as significant as it is often claimed and there are up as well as downsides. Moral of the story: don't order ten bottles of alpha ultra sigma test booster extreme because you don't look like chris bumstead after 3 months of calisthenics. If you really think your testosterone is low then get a blood test and talk to your doctor about trt if it shows your test is low.

Cortisol

Cortisol is very important for the circadian rhythm, it is perfectly normal and healthy to have higher cortisol levels sometimes, in the morning or during exercise for example. Normal levels of cortisol boost energy, which is why too low cortisol can lead to lethargy or depression. It also typically boosts motivation and enhances your focus. Cortisol can be both too high or too low and neither is desirable. Cortisol and the feeling of stress are correlated but there's more to the story, many other factors play a role.

Dopamine

Similarly, more dopamine doesn't automatically mean that you're more productive and feel better. Is a schizophrenic especially productive? What about people with tourettes or parkinson's? The homeless guy down the street doesn't seem very productive after smoking meth, even though his dopamine levels are absolutely higher than mine. Now you might say that those are extreme cases and you would be right, but it still demonstrates the point that your dopamine can both be too high or too low. The only reason most people assume their dopamine is too low is because they read it on the internet. So many other things influence your productivity, motivation and sexual function, why do people always assume it has something to do with dopamine? Maybe your high prolactin is causing your sexual dysfunction, your imbalanced norepinephrine destroys your focus or you feel lethargic all the time because your thyroid glands produce too much thyroid hormone.

You get the point, this applies to a lot more than just cortisol, dopamine and testosterone.

Conclusion

Take some time to think about whether a certain change to your body will really lead to the difference that you think it will. Don't get me wrong, supplements can have a very positive impact and I also take supplements. Just think first and don't fall for the black/white hormone A bad, supplement B good thinking.

Sources

Cortisol circadian rhythm: https://www.mdpi.com/1660-4601/18/2/676

Cortisol mental health: https://www.sciencedirect.com/science/article/abs/pii/S0165032715305036 https://www.sciencedirect.com/science/article/abs/pii/S0306453005000892 https://www.tandfonline.com/doi/epdf/10.1080/10253890500069189

Testosterone: https://pmc.ncbi.nlm.nih.gov/articles/PMC3693622/ https://pubmed.ncbi.nlm.nih.gov/21697255/ https://journals.sagepub.com/doi/10.1177/1557988314539000

Dopamine: https://pmc.ncbi.nlm.nih.gov/articles/PMC3730746/