I'm wondering if there are natural substances to boost testosterone levels? WebMD has an article about boosting testosterone, but it's mainly about managing lifestyles. Mercola also has a post about this topic that does mention some things like vitamin D, zinc, healthy fats, low sugar. Are there natural foods/berries/fruits/edibles that can be taken regularly that have the net effect of increasing testosterone?
Other than the post and the website you mentioned, here are a few more natural testosterone boosters, some of them being substances, and others being lifestyle changes or things-to-do:
1) In this study, pomegranates were found to increase salivary testosterone levels by an average of 24% (though this was averaged over both men and women, in just men, the increase was ~22%).
2) In this study, the Ashwagandha group, in conjunction with resistance training, was able to increase their testosterone by 96.2 ng/dl, compared to the placebo group, that was only able to increase their testosterone levels by 18 ng/dl.
3) In this study, significant correlations were observed between dietary intake and testosterone levels. My interpretation from the correlations in this study was that, in general, higher protein intake and higher polyunsaturated fatty acids (PUFA's) result in lower testosterone levels, while more carbohydrates, higher monounsaturated fatty acids (MUFA's) and saturated fatty acids (SFA's) result in higher testosterone levels.
4) Coming to the more controversial one, in this study, whiffing the pheromone copulin, which is secreted by ovulating females, increased salivary testosterone levels by an average of about 30%, as seen in the graph). Copulins are available on amazon; however, I have been unable to find the exact concentration of copulins used in this study and the time of exposure of the subjects to them, so proceed with your own risk.
5) The safer alternative to the above option, which depending on your circumstances, may or may not be available to you, is sexual intercourse. In this study, participants in a visit to the sex club experienced a 72% increase in testosterone levels. Even the observers experienced an 11% increase as well.
6) In this study, a 56 hours fast was observed to increase testosterone levels by 180% in normal non-obese men but not by any percentage in obese men, sadly.
7) In this study, men who chopped trees for one hour experienced a 48.6% rise in testosterone levels. I quote from the study: "A comparison of these results to the relative change in testosterone during a competitive soccer tournament in the same population reveals larger relative changes in testosterone following resource production (tree chopping), compared to competition (soccer)."
8) In this study, ingestion of 3000 mg of Royal Jelly caused an increase in testosterone levels (log testosterone levels in the RJ group was +0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL in the placebo group).
Despite what the supplement industry would have you believe, unless you are an overweight, older female, the commonly available steroid precursors (or the natural foods that claim to boost them) don't really have any effects on testosterone.
There are three precursors (Dehydroepiandrosterone or DHEA, A'dione, and A'diol) that are hormones used in endogenous (within the body, i.e. natural) testosterone production. Many of the supplements on the market that claim to boost testosterone do increase the amount of these three hormones, but in most cases, do not lead to concurrent elevations in testosterone. (There is a chart showing a study review with outcomes here).
As far as the side effects, it's best summarized by the same review paper that produced the above chart:
Significant reductions in serum HDL cholesterol of 12% and 20% have been observed after A'dione and DHEA supplementation, respectively. Similar changes have been observed after AAS injection and have been associated with the development of cardiovascular disease. Broeder et al administered either A'dione or A'diol (200 mg/d) and observed that both adversely affected HDL-cholesterol levels, low-density lipoprotein (LDL)-to-HDL cholesterol ratios, and coronary heart disease risk. Thus, it is possible that long-term supplementation could have serious side effects similar to those associated with AAS use, such as suppressed testosterone production, liver dysfunction, cardiovascular disease, testicular atrophy, male-pattern baldness, acne, and aggressive behavior. If the supplements are taken before puberty, premature closing of the epiphysis and stunted growth could occur. In women, precursor-induced increases in testosterone concentrations could cause lowered voice pitch, hirsutism (changes in hair growth patterns, including facial hair), increased abdominal fat accumulation, and general virilization. Furthermore, increases in estrogen concentrations experienced by men could have feminizing effects, including gynecomastia.
In addition to the above, there is no regulation on the supplement industry, so they may contain wildly varying levels of ingredients (Even in the same brand/line), and there have been reports of heavy metal contamination as well as contamination with actual steroid substances.
Currently, you can really sum up the supplement industry in this way: If it works, it's illegal and should be only used under a doctor's care. If it is safe to use, it probably doesn't work like they claim. Also, while many people do not realize it, if you participate in 5k fun runs, amateur cycling, or any amateur competition where the governing body adheres to USADA (or the local national equivalent) strictures, you can be subject to testing, no matter your competitive level. Many supplements would cause you to test positive if you were selected. You can always get a current list of banned supplements at the Supplement 411 site.
If interested, all of the studies referenced in the above paper are listed with links below the paper writeup itself.
One caveat: Creatine Monophosphate is a legal supplement that has been proven to do what it says. It doesn't create more muscle, but it does create a bigger pool of energy rich fluid in the muscle to draw from, so that you can work out longer, which in turn will create more muscle.