Make sure you get the right testosterone supplement for you.
Check Best ListTheobromine - The problem with theobromine is that most of the studies that shows it has any impact on testosterone production were in rats [1] and it's not been replicated in humans at all. This means that it's also quite unlikely that it will show results in humans seeing as most ingredients don't transfer effectively. And even if it did, it's likely to require far more than the maximum 400mg that is in the proprietary blend of theobromine and cacao extracts.
Cacao - Cacao contains magnesium and that can boost test [2], the problem here is twofold for our life extension review and that is simply that supplementing magnesium would be cheaper and more effective, but on top of that you probably don't get enough in this pill to make a difference in the first place as magnesium is only a tiny fraction of what's in cacao and we likely have less than 200mg in the proprietary blend.
luteolin - Luteolin is better, it's backed by several human studies [3] suggesting it can increase testosterone production and improve free testosterone levels. Luteolin is part of the bodies natural hormone production cycle. It breaks down other compounds like cholesterol and turns them into pregnenolone which the precursor hormone for testosterone. The main question of the studies was whether or not supplementing it orally would work or if the body would just produce less luteolin. And it seems that it does work to raise testosterone levels. There are however better ingredients for raising baseline test and based on common vitamin deficiency rates in the US 60% of men would do better simply taking a vitamin d, zinc and magnesium supplement. It's been shown to be effective as a supplement, but there are much better go to options to raise testosterone production and we only really rate luteolin highly if it's in a testosterone booster that has already gotten 5 or 6 other more potent ingredients right first.
1 - https://pubmed.ncbi.nlm.nih.gov/422930/
2 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696435/
3 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7139932/