In February 2022, I drew blood for the first time as a personal experiment rather than a clinical obligation. I had my results from various doctor visits over the years, but they were scattered — a testosterone reading here, a metabolic panel there, never consistent in timing, methodology, or scope. I wanted real data. Longitudinal data. The kind of dataset I'd demand in any study I reviewed before taking it seriously.
So I committed to monthly blood draws. Same lab. Same time of day (between 7:00 and 8:30 AM, fasted). Same panel. Every single month. No exceptions.
Thirty-six consecutive months later, I'm sitting on a dataset that has fundamentally changed how I think about hormonal health — my own and everyone else's. Some of what I found confirmed what the literature predicts. Some of it genuinely surprised me. And one finding in particular made me realize that the way most men approach testosterone testing is almost completely useless.
The 14 Biomarkers I Track
Every month, I measure the same panel:
- Total Testosterone — the headline number everyone focuses on
- Free Testosterone — the biologically active fraction that actually matters
- SHBG — Sex Hormone-Binding Globulin, which determines how much T is "trapped"
- LH — Luteinizing Hormone, the signal from pituitary to testes
- FSH — Follicle-Stimulating Hormone, LH's partner in the HPG axis
- DHEAS — Dehydroepiandrosterone sulfate, a key androgen precursor
- Estradiol — the primary estrogen, produced partly from testosterone via aromatase
- Cortisol — the stress hormone that antagonizes testosterone
- TSH — Thyroid-Stimulating Hormone, because thyroid function affects everything
- Fasting Insulin — a proxy for metabolic health and insulin sensitivity
- hsCRP — high-sensitivity C-reactive protein, a marker of systemic inflammation
- Vitamin D — because it functions more like a hormone than a vitamin
- Ferritin — iron stores, which affect energy and oxygen transport
- CBC — Complete Blood Count, the general health baseline
This panel costs me roughly $180-220 per draw, depending on the lab. Over three years, I've spent somewhere around $7,000 on blood work alone. I consider it the best investment I've made in my own health, because it replaced guessing with knowing.
The Biggest Surprise: How Much Testosterone Fluctuates
Before I started this project, I assumed testosterone was relatively stable — that barring major lifestyle changes, my levels would hover around a set point with minor variation. I was wrong.
Over 36 months, my total testosterone readings have covered an enormous range — from a devastating low of 187 ng/dL during the post-TRT crash I've detailed in my personal article, to a peak of 687 ng/dL once I found an intervention that worked. That full journey is a story in itself. But the more scientifically interesting data comes from the ~24 months after I stabilized on my current protocol. Across that stable period — with no significant changes to my supplement regimen, training, or diet — my total testosterone still ranged from 412 to 687 ng/dL. That's a 275-point spread in a "stable" man. Some of this variation is biological noise, measurement variability, and the pulsatile nature of hormone secretion. But some of it is real and patterned.
Seasonal Variation Is Real
When I plotted my data month by month, a clear seasonal pattern emerged. My testosterone consistently peaked in late summer (July-August) and troughed in late winter (January-February). The difference between seasonal peaks and troughs averaged about 80-110 ng/dL.
This tracks with existing literature. A study in the Journal of Clinical Endocrinology & Metabolism documented seasonal testosterone fluctuation correlated with sunlight exposure and vitamin D synthesis. My own vitamin D levels followed an almost identical seasonal curve, lagging testosterone by about 4-6 weeks. The relationship isn't coincidental — vitamin D receptors exist in Leydig cells and appear to play a regulatory role in testosterone synthesis.
The practical implication is significant. If you get your testosterone tested once — in February, after a dark winter, during a stressful period at work — you might get a reading that's 100+ ng/dL lower than your summer baseline. That single data point could lead to a diagnosis of "low testosterone" and a prescription for TRT. But it might not represent your actual hormonal status at all. It might just represent February.
Sleep Debt: The Fastest Way to Tank Your Testosterone
I knew from the literature that sleep deprivation affects testosterone. What I didn't appreciate until I lived it — and measured it — was how fast and how severe the effect is.
On three separate occasions during the tracking period, I had stretches of poor sleep — two to three consecutive nights of fewer than 5.5 hours. In each case, my next blood draw (typically within 48 hours of the sleep disruption) showed total T drops of 60-80 ng/dL from my recent trend line. Not percentage. Absolute values. My free T dropped proportionally.
The recovery was equally informative. After returning to normal sleep patterns, my testosterone bounced back within about 7-10 days. The effect was acute, dramatic, and reversible — which is actually good news. It means sleep isn't just a lifestyle recommendation for testosterone optimization. It's a direct, mechanistic input with measurable, rapid effects.
Alcohol: The 48-72 Hour Testosterone Tax
I'm not a heavy drinker, but I'm not a teetotaler either. During the tracking period, I had several occasions of moderate social drinking — three to four drinks in an evening. When blood draws fell within 48-72 hours of these events, the data was consistent: total T was suppressed by roughly 40-60 ng/dL compared to my rolling average.
The mechanism is well-documented. Alcohol directly inhibits testicular testosterone production, increases cortisol (which suppresses GnRH), and promotes aromatase activity (converting more T to estrogen). What my personal data added was a timeline: the suppressive effect lasted approximately 48-72 hours, with full recovery by day 4-5. This isn't a reason for total abstinence. But it's a reason to be thoughtful about timing — especially if you're getting bloodwork done or trying to assess how a supplement protocol is working.
Training: The Overtraining Trap
I train with weights four days per week and have for years. During the tracking period, there were two stretches — each lasting about 3-4 weeks — where I significantly increased volume and intensity, driven by goal-oriented thinking rather than recovery-aware programming.
Both times, the pattern was identical. Cortisol climbed steadily across the overtraining period, peaking about 30-40% above my baseline. Testosterone dropped in lockstep, falling 50-70 ng/dL below trend. The cortisol-testosterone inverse correlation in my dataset was one of the tightest relationships I observed — they moved in near-perfect opposition.
This confirmed what the exercise physiology literature describes as the overtraining-induced hormonal suppression pattern. Training stimulates testosterone acutely. Overtraining — training beyond your recovery capacity — does the opposite. The line between the two is individual and invisible without data. For me, pushing past four intense sessions per week consistently tipped the balance from anabolic to catabolic.
The Most Stable Predictor: Body Fat Percentage
Of all the variables I tracked — sleep, stress, training, alcohol, supplements, season — the single most stable predictor of my testosterone trend was body fat percentage. Not day-to-day fluctuations, but the medium-term trend.
During the stable period of tracking, my body fat ranged from roughly 18% down to about 13% at my leanest. The correlation with testosterone was striking. When I was above 16%, my average total T hovered around 450-500. When I got below 15%, it climbed to the 550-650 range. The relationship was nearly linear across that range.
This makes biochemical sense. Adipose tissue contains aromatase, which converts testosterone to estradiol. More body fat means more aromatase activity, more T-to-estrogen conversion, and lower net testosterone. My estradiol readings confirmed this — they tracked almost perfectly with body fat percentage, rising when fat increased and falling when it decreased.
Getting lean wasn't just cosmetic. It was hormonal infrastructure.
Where I Am Now
As of my most recent panel, my numbers sit in a range I'm genuinely satisfied with. Total T consistently in the mid-600s, free T in the upper quartile of the reference range, SHBG in a healthy but not elevated range, cortisol well-managed, inflammation markers low, and LH/FSH stable — indicating my body is producing its own testosterone through its own machinery, not receiving it from outside.
I credit this to a combination of factors: body composition management (staying below 15% body fat), consistent but not excessive training, prioritizing sleep above almost everything else, managing stress actively, and the compound I write about elsewhere on this site — the one that passed both my evidence framework and my HPG axis criteria. I started it in mid-2023, and the trend line shifted noticeably within about 8-10 weeks. Not dramatically. Not miraculously. But measurably — and sustainably, over the subsequent 18 months.
The Real Takeaway: Single Tests Are Nearly Meaningless
If there's one thing 36 months of data taught me, it's this: a single testosterone test tells you almost nothing. Your testosterone at any given moment is the sum of your genetics, your sleep over the past week, your stress levels, your body fat, your training load, what you drank last weekend, what season it is, and probably a dozen other variables I'm not even tracking.
A single blood draw captures one instant in a system that fluctuates by 200+ ng/dL over the course of a year. Making medical decisions based on that one data point is like checking the weather at 6 AM and deciding whether to bring an umbrella for the entire week.
Trends over time are everything. If you're serious about understanding your hormonal health, test at least quarterly — same lab, same time of day, same conditions. Build a dataset. Look for patterns. And when you make changes — whether it's a supplement, a training modification, or a sleep intervention — give it at least 8-12 weeks and multiple blood draws before you decide whether it's working.
The body doesn't speak in headlines. It speaks in trends. You just have to listen long enough to hear it.
This article reflects my personal data and experience. Individual hormonal profiles vary significantly. If you're concerned about your testosterone levels, work with a qualified endocrinologist. For the science behind the hormonal mechanisms discussed here, see my articles on testosterone decline and the HPG axis.