Do Testosterone-Boosting Supplements Really Work? My N=1 Study Results
- © Nils Osmar 2025. Updated May 19, 2025
- This post is not intended as, and should not be taken as, medical advice.
- See full Medical Disclaimer
In this article, I’ll be sharing information about my latest testosterone and free testosterone test results – with and without having taken supplements before the tests.
Things to Think About
As we age our testosterone tends to drop. The decline is gradual, starting around the age of thirty, As the authors of one study put it:
Longitudinal studies in male aging studies have shown that serum testosterone levels decline with age (Harman et al 2001; Feldman et al 2002). Total testosterone levels fall at an average of 1.6% per year whilst free and bioavailable levels fall by 2%–3% per year.
The reduction in free and bioavailable testosterone levels is larger because aging is also associated with increases in SHBG levels (Feldman et al 2002). During the course of longitudinal studies some men may develop pathologies which accentuate decreases in testosterone levels…
The changes in average serum testosterone levels with aging mean that the proportion of men fulfilling a biochemically defined diagnosis of hypogonadism increases with aging. Twenty percent of men aged over 60 have total testosterone levels below the normal range and the figure rises to 50% in those aged over 80. The figures concerning free testosterone are even higher as would be expected in view of the concurrent decrease in SHBG levels (Harman et al 2001).
My Experience
- I’m 72 at the time that I’m writing this; but I started noticing a decline in my T levels when I was in my fifties. This may because I was eating a vegan diet at the time. Vegan diets may work for some people, but it was not a good diet for me. I initially lost weight, then started gaining body fat; my mind felt muddled, and I started developing memory issues; and my teeth started hurting. When I added meat back into my diet, all of these problems resolved.
- But by the time I in my mid-sixties, even while including more meat in my diet, they were dropping again.
- My doctor said not to worry about it, that I was just experiencing “normal aging. ” I told him I wasn’t interested in aging normally, but in keeping my biomarkers young. He looked at me blankly, and I realized I was on my own.
- I made some dietary changes (eating more meat and fewer carbohydrates, which helped a bit. The fact that I lost body fat when I ate more meat was likely a factor, as more body fat also correlates with a drop in testosterone levels.
- But even with these changes in my diet, my levels were still dropping as time went by. A few years ago, I started taking supplements to see if they might help.
My N=1 Study
To confirm whether T-boosting supplements work for me, I recently two blood tests, about a month apart.
In the first test, on March 15th…
- I did not change my diet, workout regimen or my hours of sleep. (I wanted the supplements to be the only variable)
- I did not take any supplements for two days before my blood test.
My results
- My testosterone (when not taking supplements) came in at 453 ng/dL (not terrible, but not great).
- My free T was 11.4 pg/mL (also not great).
In the second test, on April 22nd…
- I did not change my diet, workout regimen or my hours of sleep..
- I did take the supplements (per my usual morning routine), about 1.5 hours before my blood was drawn.
My results
- My testosterone this time was 736 ng/dL (Much better)
- My free T was 13.9 pg/mL (still not as high as I’d like, but better.)
Previous tests
- This is the third time I’ve tested my testosterone “with and without taking supplements”.
- The result is always the same: When I take the supplements, my testosterone and free T are much higher.
The supplements I took this time
- I actually take over twenty different anabolic supplements, but on different days. (Each stack has 10-11 supplements in it.)
- For this test I was taking my Monday-Wednesday stack.
My Monday-Wednesday Anabolic Supplements
- Boron – May lower SHBG (sex hormone-binding globulin) and increase free testosterone levels.
- DHEA – Hormone precursor to testosterone and estrogen; supports hormone balance and testosterone production.
- EAA – Essential amino acids; take before workout to support muscle protein synthesis.
- Fadogia Agrestis – Traditional herb with potential testosterone-boosting effects; limited clinical evidence and safety data.
- L-Leucine – Branched-chain amino acid (BCAA) that stimulates muscle protein synthesis; may support hGH (human growth hormone) release.
- L-Ornithine – Amino acid that may support hGH release, particularly during sleep or exercise.
- Super Miraforte – Often contains zinc and stinging nettle root; may lower SHBG and support free testosterone levels.
- Vitamin B6 – Supports neurotransmitter synthesis (e.g., serotonin, dopamine) and hGH production; aids hormone regulation.
- Vitamin D3 – Supports testosterone production, immune function, bone health, and mood regulation.
- Zinc + Copper – Zinc supports testosterone synthesis and immune function; copper balances zinc intake to prevent deficiency.
- DIM (Diindolylmethane) – Modulates estrogen metabolism by promoting beneficial estrogen metabolites (2-hydroxyestrone) and supports hormone balance.
Why so many?
- I started combining them because some “combination” supplements I’d gotten good results from did so.
- But the combinations in the “multis” were proprietary blends which did not give any information on the amounts taken.
- Doing it this way I can adjust the doses and keep better track of the results.
My Thursday-Saturday Anabolic Supplements
My other stack (which I take Thursday-Saturday) is listed below. To be clear, I was not taking this stack this time.
- Calcium D-Glucarate – Supports detoxification by aiding liver enzyme activity (glucuronidation) and may help regulate hormone metabolism.
- Cistanche Tubulosa – Traditional herb linked to improved vitality and potential testosterone support; may enhance energy and libido.
- DIM (Diindolylmethane) – Modulates estrogen metabolism by promoting beneficial estrogen metabolites (2-hydroxyestrone) and supports hormone balance.
- HMB (β-Hydroxy β-Methylbutyrate) – Reduces muscle protein breakdown, supports muscle recovery, and may enhance exercise performance.
- Horny Goat Weed – Contains icariin, which supports libido and blood flow via PDE5 inhibition (similar to Viagra’s mechanism).
- Niacin – Supports lipid management (lowers LDL, raises HDL) and may transiently increase hGH release at high doses.
- Pregnenolone – Precursor to DHEA, progesterone, and other hormones; supports overall hormone synthesis and balance.
- Tongkat Ali – May boost free testosterone by reducing cortisol and SHBG; supports energy, libido, and stress resilience.
- Tribulus – Often used for libido and athletic performance; effects on testosterone are inconsistent in studies.
- Astragalus – Supports longer telomeres
My Workouts
Working out with weights also correlates, for me, with improved testosterone levels. I do an upper body workout twice a week and a lower body/core workout twice a week (leaving 2-3 recovery days between workouts).
My Conclusion
- T-boosting supplements (at least the one ones on my Mon-Wed. list), when combined with workouts, do appear to be working for me.
- As this test shows, both my free T and total T were higher when I was taking them.
- My sex drive and workout results tend to be higher during periods when I’m taking T boosting supplements.
I wanted some supplements in each list that lower estrogen, some the increase testosterone, some that raise hGH levels, some the lower SHBG; I used AI to create two lists which include all of the above. I take each stack for three days then switch to the other. My first objective is to find out which list works best. At that point I plan to test the individual supplements in each stack.
Why Not Just Get Testosterone Injections?
- Getting hormone injections work well for some men. But I plan on avoiding them as long as I can.
- This is partly because of the cost (supplements are cheaper).
- It’s also, in part, because when we start taking injections, we become dependent on them.
- For men, that means that our testicles shut down and stop functioning. Some men are able to “reactivate” them after stopping injections, but some are not.
- I’m getting good results with a combination of eating meat, working out and taking supplements. If that ever changes, I’ll consider hormone replacement therapy.
Your results may vary
- My recent N=1 studies have established to my satisfaction that T-boosters (at least the ones on my Monday-Wednesday list) work for me.
- This doesn’t necessarily mean they will work for everyone.
- I don’t sell testosterone boosting supplements, and have absolutely no stake in whether anyone else takes them. (I’m not trying to “sell you” on taking them.) I also don’t care whether anyone else “believes in” them. (You are free to believe whatever you like. And you could be right – the fact that they worked for me, does not mean they’ll necessarily work for you.)
- If you are taking T-boosters, I would encourage you to do a similar blood test and report your results in the comments below.
My Workouts
As I mentioned above, I do upper body workouts twice a week and lower body/core workouts twice a week. Compounds exercise appear to be particularly helpful for increasing testosterone, because they involve multiple joints and muscles working together. They’ve been found to be effective for stimulating hormonal responses.
But again –speaking only for myself — my results are better if I work out while also taking anabolic supplements, then if I skip the supplements.
Chin-ups and pull-ups are among my favorite upper body compound exercises. The one I’m doing at the start of the video below (from this morning’s workout) can be done by people with any level of fitness; I’m using a tower which lets me brace my feet on a bar a few inches off of the floor. This allows me to do many more reps and sets than I would if I were doing “unassisted” chin-ups.
These are a few of my upper body exercises. Some are compound, others work individual muscles.
Then and Now
- This was me back in the fall of 2021.
- I had just bought my power tower but hadn’t started working out yet.
- Luckily I had the thought of making a “before” video.
- In those days, I was following Dr. Valter Longo’s “longevity” diet. But I found that on it, I was visibly losing muscle.
- Note: I was actually taking some T-boosting supplements at that time, but I was not building any muscle, because I was not working out.
Me Today
- The video above is me four years ago. The one below is me in April 2025: Age 72.4. 5’11” tall. 185 pounds.
- Obviously there are bigger/stronger/more muscular guys in the world, but I’m happy with the gains I’ve been able to make.
Working Out in My Home Gym
This isn’t my whole workout, just a few of the exercises I’m doing these days;
“What About NMN, and Other Anti-Aging Supplements?”
I’m still taking many other supplements such as NMN (which boosts NAD+), taurine, glycine with NAC and several others for general anti-aging; but in this article I’m focusing on the ones associated with boosting testosterone. If you’re curious about my early morning supplements, see this page:
AI weighs in
- I told an AI movie maker I’d conducted a “study,” uploaded my photo and asked it to imagine the study – it came up with this 😊
Not medical advice
This article is not intended as, and should not be taken as, medical advice. I’m not advising that people eat any particular diet or take any particular supplement(s), just reporting on what I’m doing. Supplements, like medications and other interventions, can have side effects; I would encourage people to research both possible benefits and side effects before starting on any supplementation regimen, and consult with a medical professional about any issues which might have a medical component. See full Medical Disclaimer
Other resources
- My Youtube channel Pathways to Longevity
- My Facebook group: Anti-Aging and Life Extension,
