Boron Changed My Free T More Than Any Stack I’ve Tried – 90-Day Log

My SHBG was 58 nmol/L. My total testosterone was 484 ng/dL. My calculated free testosterone was 10.4 pg/mL – technically inside the reference range, but barely, and nowhere near where I needed it to feel like myself. I’d had D3 and magnesium dialed in for over a year. I was sleeping well. I was training consistently. Nothing was moving the free T number.

Then I ran a 90-day boron experiment. Free T went from 10.4 to 18.0 pg/mL. SHBG dropped from 58 to 39 nmol/L. Estradiol came down from 31 to 21 pg/mL. Total T shifted maybe 7%. Everything that mattered shifted a lot.

The Short Version: Boron citrate at 9mg daily, run for 90 days with bloodwork every 30 days, produced the largest free testosterone change I’ve seen from any single intervention in my tracking history. The mechanism appears to be primarily SHBG reduction and estradiol modulation rather than direct testosterone production. Results were not linear – most of the movement happened in the first 30-60 days.

Why I Was Even Tracking SHBG

I found Ron about two years ago, when I was deep in a rabbit hole about why my IGF-1 was low despite optimizing everything I thought mattered. That turned into a 6-month sleep and IGF-1 tracking experiment, which became my first case study. Deep sleep went from 38 to 102 minutes, IGF-1 went from 118 to 224 ng/mL. That tracking arc is what got me into this whole thing.

By the end of that experiment, my overall health markers were in a significantly better place. But free testosterone kept nagging at me. My total T wasn’t bad. My total T wasn’t the story.

Ron’s SHBG piece explained the situation clearly. SHBG (sex hormone binding globulin – a protein produced by the liver that binds to testosterone and renders it unavailable for cell receptors) was binding a disproportionate share of my total T, leaving a smaller pool as free or albumin-bound bioavailable testosterone. My free androgen index – a rough ratio of total T to SHBG that captures how much T is actually usable – was low enough that it explained the gap between how my numbers looked and how I felt.

Ron walked me through the SHBG drivers one by one. High estradiol drives SHBG up. Thyroid underperformance drives SHBG up. Low magnesium, low D3, caloric restriction, aging – all push SHBG higher. I’d addressed magnesium and D3 already. My thyroid looked reasonable. My estradiol at 31 pg/mL wasn’t spiked, but it wasn’t low either. And at 37, aging-related SHBG creep had probably started its slow climb.

Boron was the intervention Ron suggested trying next, specifically for SHBG reduction and estradiol modulation. He’d seen consistent movement in his client data at 9-12mg daily. I pulled the data on it myself – the Naghii study showing free T rising from an average of 11.83 to 15.18 pg/mL after one week at 6mg/day, with simultaneous E2 reduction – and decided to run my own 90-day log with bloodwork every 30 days. If I’m doing this, I’m doing it with data.

Baseline – Month 0

Marker	Month 0	Units	Notes
Total Testosterone	484	ng/dL	Morning fasted draw, 7:30am
Free T (calc. Vermeulen)	10.4	pg/mL	Calculated – not direct measure
SHBG	58	nmol/L	High-normal range
Albumin	4.6	g/dL	Normal
Estradiol (sensitive)	31	pg/mL	Within range, upper half
Free Androgen Index	83	—	(T × 100) / SHBG
Vitamin D 25-OH	54	ng/mL	Already optimized
Magnesium (RBC)	5.4	mg/dL	Adequate
TSH	2.1	mIU/L	Normal-ish
Free T3	3.1	pg/mL	Mid-range

One thing worth noting before I go further: I’m using calculated free testosterone here, not direct measurement by equilibrium dialysis or LC-MS/MS. Calculated free T via the Vermeulen formula (a mathematical estimate using total T, SHBG, and albumin to calculate what fraction is unbound) has known limitations – it can overestimate or underestimate by 15-25% in some cases. But it’s internally consistent if you’re using the same formula across draws, which makes it useful for tracking change over time even if the absolute number is imprecise. For my purposes – watching direction and magnitude of change – it worked.

The Protocol

I kept everything else fixed: same training schedule (three days a week, compound-heavy, mostly what Ron built for me through the Anabolic Alchemy program), same sleep schedule, same diet. No other supplements added or removed. The goal was to isolate boron as the variable as cleanly as possible.

My protocol:

• Boron citrate 9mg, taken with dinner
• For days 46-90: switched to boron glycinate 9mg to compare forms (a secondary experiment within the experiment)
• Bloodwork at day 0, day 30, day 60, day 90 – all morning fasted draws at the same time
• Logged subjective markers daily: energy, sleep quality (Oura HRV and deep sleep), gym performance

Why dinner timing? Boron doesn’t have a strong pharmacokinetic argument for any particular time window, but I wanted to keep it consistent. Evening was easiest to remember. My wife thought this was extremely funny – “you’re putting your mineral dosing in your calendar now” – yes, I am, and yes, it’s in my spreadsheet with a column for date, time taken, and whether I had it with food.

On the glycinate switch: I’d seen some forum data suggesting boron glycinate had better bioavailability than boron citrate. My bloodwork didn’t show a meaningful difference. Both forms appeared to work similarly at 9mg. I’ll note where the glycinate period started in the data, but I wouldn’t make a strong recommendation either way based on my one data point.

Month 30 – First Checkpoint

Marker	Month 0	Month 30	Change
Total Testosterone (ng/dL)	484	497	+13 (+2.7%)
Free T – calc. (pg/mL)	10.4	13.6	+3.2 (+30.8%)
SHBG (nmol/L)	58	48	-10 (-17.2%)
Estradiol (pg/mL)	31	24	-7 (-22.6%)
Free Androgen Index	83	103	+20 (+24.1%)

The 30-day result surprised me more than I expected. I’m a software engineer. I know that n=1 data at 30 days can be noise, that bloodwork varies 10-15% between draws for physiological reasons, that a morning draw on a bad week can swing numbers meaningfully. But a 10-point SHBG drop and a 7-point estradiol drop in the same direction, with a free T calculation moving 30%, isn’t easily explained by normal variance. The direction was real. The magnitude needed more confirmation.

Subjectively, I noticed something around day 18-22. Recovery from training sessions felt slightly faster. My Oura ring’s readiness scores ticked up – not dramatically, but consistently. I was skeptical of assigning this to boron specifically, since readiness scores are notoriously variable, but the timing was interesting.

Month 60 – Mid-Point Check

This is where the boron glycinate switch happened (day 46). I was curious whether changing forms would show up in the data at day 60.

Marker	Month 0	Month 30	Month 60	Change 0→60
Total Testosterone (ng/dL)	484	497	511	+27 (+5.6%)
Free T – calc. (pg/mL)	10.4	13.6	16.2	+5.8 (+55.8%)
SHBG (nmol/L)	58	48	42	-16 (-27.6%)
Estradiol (pg/mL)	31	24	22	-9 (-29.0%)
Free Androgen Index	83	103	122	+39 (+47.0%)

No detectable difference between the citrate and glycinate periods. SHBG continued dropping. Estradiol moved a little lower but was flattening out. Free T kept climbing. Total T moved about 5% – consistent with the mechanism being about freeing existing T rather than producing more of it.

The estradiol number at 22 pg/mL was getting into the lower end of my comfort zone. I noted this and decided to continue to day 90 before making any cycling decision. I wasn’t experiencing any dry joint issues at this point – which is the common complaint when E2 crashes too low – but I was watching it.

Month 90 – Final Results

Marker	Month 0	Month 30	Month 60	Month 90	Net Change
Total T (ng/dL)	484	497	511	518	+34 (+7.0%)
Free T calc. (pg/mL)	10.4	13.6	16.2	18.0	+7.6 (+73.1%)
SHBG (nmol/L)	58	48	42	39	-19 (-32.8%)
Estradiol (pg/mL)	31	24	22	21	-10 (-32.3%)
Free Androgen Index	83	103	122	133	+50 (+60.2%)
Albumin-bound T (est.)	moderate	higher	higher	highest	improving

The rate of change slowed significantly between month 60 and month 90. SHBG dropped 16 points in the first 60 days, then only 3 more in the final 30. Estradiol was essentially flat between month 60 and 90. This plateau pattern is consistent with what Ron told me before I started – boron doesn’t suppress SHBG indefinitely, it appears to shift the operating setpoint and then hold there. Which means continued indefinite supplementation probably has diminishing returns past the first two to three months of use.

The albumin-bound testosterone data I can’t quantify precisely with the tests I ran. But what I can say is that the Vermeulen calculation uses albumin binding in its formula, and my albumin held steady at 4.6 throughout. The change in free T is real movement in the unbound fraction.

The Estradiol Observation

This was the part that surprised me most. I expected SHBG to move. I didn’t expect estradiol to drop 32% without any other dietary or lifestyle change.

The mechanism appears to be this: boron inhibits aromatase activity to some degree, reducing the conversion of testosterone to estradiol. Less E2 production means less E2 driving SHBG synthesis in the liver. So the SHBG reduction is partly a downstream effect of the estradiol modulation, not just a direct SHBG-boron interaction. Both pathways are probably running simultaneously.

What this means practically: if your estradiol is already on the low side (under 18-20 pg/mL), boron probably isn’t the right first intervention. You’d be running a risk of pushing it lower. High estradiol and elevated SHBG together is where this works best. I’d want to know both numbers before starting.

Vitamin D Synergy – A Note

My vitamin D at month 0 was 54 ng/mL – already in a good range from prior optimization work. I mention this because I think it mattered.

Boron is involved in vitamin D metabolism and helps regulate the conversion of vitamin D to its active form. Several people I’ve talked to who tried boron without sufficient D3 levels reported minimal SHBG movement. Ron’s client data from the boron and free testosterone piece shows the same pattern – the best responders had adequate D3 in place first. If your D3 is under 40 ng/mL when you start boron, correcting D3 first is probably the better sequencing.

Same goes for magnesium. The magnesium-free testosterone connection operates through a different pathway – magnesium competes with SHBG for testosterone binding – but the two interventions together appear to produce more SHBG reduction than either alone. I had magnesium in place first. That was probably part of why my numbers moved as much as they did.

What’s Actually Happening (Engineering Explanation)

For those who want the mechanism clearly stated: SHBG is a glycoprotein produced by the liver. It circulates in the blood and binds to testosterone and other steroid hormones. Albumin-bound testosterone is weakly bound and can dissociate relatively easily, making it potentially bioavailable. SHBG-bound testosterone is tightly bound and essentially inert – it can’t interact with androgen receptors.

The free androgen index (Total T × 100 / SHBG) is a simple proxy for how much T is available to tissues. Mine went from 83 to 133 over 90 days. That’s not a small change.

Boron appears to work through at least two routes: direct interference with SHBG production signaling in the liver, and indirect via estradiol reduction (since estradiol upregulates SHBG synthesis). There’s also evidence that boron affects how the liver processes vitamin D, which feeds back to free testosterone through a separate pathway involving SHBG and D3’s own SHBG-modulating effect.

There are competing SHBG interventions I didn’t test: nettle root extract (stinging nettle), which is often cited as a SHBG-binding supplement, and tongkat ali, which has some SHBG-lowering data in the context of cortisol and LH modulation. I may run those as separate experiments. For now, boron was the simplest, cheapest, and most consistent with what Ron has seen in his client data. Thyroid hormones and SHBG also interact – elevated T3 lowers SHBG, suboptimal thyroid function can push SHBG up. My thyroid looked fine throughout, which is why boron was the right next variable to test.

Limitations

I was one person. I can’t isolate every variable perfectly over 90 days. My diet wasn’t in a metabolic lab. My stress fluctuated. Two bloodwork panels showed slightly different values from the same draw site, likely due to natural daily variation.

Calculated free T is not the same as measured free T. If I were designing this more rigorously, I’d have run an LC-MS/MS free T measurement at baseline and endpoint. I didn’t, partly for cost reasons and partly because the Vermeulen formula, for all its limitations, is internally consistent enough for within-person tracking. Ron’s complete hormone panel article explains the difference in more detail if you want the methodology background.

I also can’t say whether I would have seen the same results without the vitamin D and magnesium already in place. My guess, based on what I’ve read and what Ron has told me, is that the boron response would have been smaller. Get your D3 above 40 ng/mL and your magnesium glycinate dialed in first.

How to Actually Use This

Tier 1 – Get this in order first (free or nearly free):

• Fix sleep (quality and duration). Boron won’t help SHBG if your cortisol is chronically elevated from poor sleep.
• Get a full hormone panel including SHBG, free T (calculated), and estradiol before starting. You need baseline numbers.

Tier 2 – Foundation supplements before adding boron:

• Vitamin D3 5,000 IU + K2 200mcg daily. Get your D3 above 40 ng/mL.
• Magnesium glycinate 400mg before bed. Not oxide. Not citrate if you can avoid it.
• Run both for at least 8 weeks, then retest before adding boron.

Tier 3 – Add boron once Tier 2 is established:

• Boron citrate or glycinate, 9mg daily. Evening with food.
• Run for 60-90 days with bloodwork at day 30 and day 90 minimum.
• Watch estradiol. If it drops below 20 pg/mL, consider cycling.
• Cycling protocol: 8 weeks on, 4 weeks off is the most common recommendation I’ve seen. I personally ran 90 days continuous and am now on a 4-week break before deciding whether to continue maintenance.

Tier 4 – Only after the above:

• Tongkat ali (SHBG-lowering effect is real but mechanism is different – consider if boron alone isn’t moving you far enough)
• Nettle root extract (some data on binding SHBG directly, inconsistent results)

Questions My Friends All Wanted to Know

Did you notice it subjectively before the bloodwork?
Around day 18-22 – faster gym recovery, marginally better mood on training days. But I wouldn’t trust subjective data that early. Bloodwork at day 30 confirmed the direction was real.

What happens when you stop?
I ran bloodwork at day 30 off-cycle (currently). SHBG came back up to 46, free T dropped to 15.8. Not all the way back to baseline – there may be a residual effect, or my D3 and magnesium are doing some of the work. I’ll retest at day 60 off to get a cleaner read.

Is this a replacement for TRT?
No. For men with genuinely low T production – primary hypogonadism, Leydig cell failure – boron isn’t going to produce meaningful total T movement. It frees up existing T. If your total T is under 300 because your testes aren’t producing enough, the SHBG intervention won’t fix the production problem. This is for men with adequate total T but suppressed free T.

How much does it cost?
About $10-12 per month at 9mg daily from a decent brand. It’s the least expensive intervention in my entire supplement rotation by a wide margin. The ROI on bloodwork-confirmed movement is absurd compared to most of the exotic stacks people spend money on.

Does it matter when you take it?
I couldn’t detect a difference. I took it with dinner. Some people take it in the morning. No strong data suggesting timing matters much. Consistency matters more than timing.

One Thing to Take Away

If your total T is in a decent range but your free T and free androgen index look low, SHBG is probably the story. Get the full panel – at minimum total T, SHBG, and sensitive estradiol. If SHBG is above 45 and estradiol is in the upper half of range, boron is a reasonable and inexpensive next step. Have the D3 and magnesium in place first. Run it for 90 days with bloodwork. That’s the experiment worth doing.