Does lowering prolactin actually raise testosterone levels?

What did @santacruzmedicinals actually say?

The video, featuring Lucas Aoun from Ergogenic Health, argues that sex hormone-binding globulin (SHBG) is a hormone that "binds to and renders testosterone inactive in the body" and that chronically elevated levels can produce symptoms of low testosterone. They then offer three interventions: supplementing boron, lowering ferritin (liver iron), and eating enough carbohydrates to avoid the SHBG-raising effects of ketogenic or carnivore diets.

To their credit, the creators actually define the mechanism before pitching solutions, which is more than most TikTok hormone content does. The framing of SHBG "stealing" testosterone is dramatic but not entirely wrong as a lay explanation of how binding globulins work.

Does the science back this up?

Partially, yes. The core biology is solid, but the evidence behind the three interventions ranges from promising to pretty thin. Boron has real data behind it; the ferritin-SHBG link is real but more nuanced than presented; and the carb claim is supported by some evidence but overstated.

On boron: a 2015 study by Pizzorno in the journal Integrative Medicine reviewed evidence that boron supplementation was associated with reduced SHBG and increased free testosterone in men. Earlier work by Naghii and Samman (1997, Journal of Nutritional Biochemistry) also showed hormonal shifts after boron supplementation in healthy men. The effect sizes are real but modest, and most studies are small.

On ferritin: iron overload is associated with liver dysfunction, and the liver is where SHBG is synthesized. A 2018 analysis published in Clinical Endocrinology confirmed associations between markers of liver health and SHBG levels. However, the video implies that managing ferritin is a straightforward lever for SHBG, which skips over the complexity of iron metabolism entirely.

On carbohydrates: a 2018 study by Hamalainen and colleagues in Journal of Steroid Biochemistry and Molecular Biology showed that low-fat, high-fiber diets affected SHBG and testosterone. Some research does support that very low carbohydrate intake can raise SHBG, though the effect is not universal and depends on overall caloric intake, protein, and individual metabolic context.

What did they get wrong (or right)?

The biggest problem here is the ferritin claim. Saying elevated liver iron raises SHBG collapses a complicated metabolic relationship into a simple cause-and-effect that the evidence does not cleanly support. SHBG production is regulated by multiple hepatic signals, including insulin, thyroid hormones, and inflammatory cytokines. Ferritin is one piece of the puzzle, not the driver.

The SHBG-as-hormone framing is also slightly off. SHBG is technically a glycoprotein, not a hormone in the classical sense. It does not signal through a receptor cascade the way testosterone does. Calling it a hormone that "steals" testosterone is a useful simplification but could mislead viewers into thinking SHBG itself is something the body produces to work against them, rather than a transport protein with legitimate physiological roles including potentially protective cardiovascular effects noted by Ding et al. (2009, JAMA Internal Medicine).

What they got right: SHBG does bind testosterone and reduce its bioavailability. Chronically elevated SHBG can produce symptoms consistent with hypogonadism even when total testosterone looks normal. These are clinically relevant points that are often ignored in mainstream discussion.

What should you actually know?

If you are seeing symptoms of low testosterone but your labs show normal total testosterone, asking your provider to check SHBG and calculate free testosterone is legitimate and worthwhile. The video is correct that total testosterone alone does not tell the full story.

However, self-managing SHBG with boron and carb adjustments, without understanding why your SHBG is elevated, is getting ahead of the data. High SHBG can be a sign of liver disease, thyroid dysfunction, or inadequate caloric intake. Treating the number without investigating the cause is bad medicine.

Boron supplementation at doses used in studies is generally considered low-risk, but results vary. The carbohydrate point is reasonable dietary advice for anyone on a very restrictive diet who is experiencing hormonal symptoms, but it is not a substitute for proper endocrine evaluation. Anyone with symptoms of hypogonadism should work with a licensed clinician, not a supplement stack from a TikTok video.