What did @freebirdbros actually say?
In a comedic guessing game format, the creators claimed that Japan, South Korea, Italy, and Thailand rank as the four countries with the lowest testosterone levels globally. Japan got the top spot, with South Korea second. Along the way, they threw in casual explanations: South Korea's low testosterone is why men there "are small," and Japan's association with anime and sushi explains its ranking. None of these explanations were sourced. The video is framed as a joke, but the underlying claim, that specific countries rank lowest for testosterone, is presented as factual enough that viewers are meant to walk away believing it.
The framing matters here. Comedy packaging does not neutralize a health claim reaching 773,000 viewers. When someone says "South Korea is number 2 for the lowest amount of testosterone" without citing a single study, that is a health claim, full stop.
Does the science back this up?
Partially, and with heavy caveats. There is legitimate research showing population-level testosterone differences across countries, but the data is messier and more qualified than any top-four list implies.
A large cross-national study by Travison et al. (2007, Journal of Clinical Endocrinology and Metabolism) documented declining testosterone levels in American men over decades, and similar secular declines have been observed in European and East Asian cohorts. Research by Hu et al. (2020, Frontiers in Endocrinology) found that men in East Asian populations, including Chinese and Japanese cohorts, showed lower mean serum testosterone compared to Western European and North American samples, though the differences were often modest and confounded by age, BMI, and assay methodology.
A 2021 meta-analysis by Golestani et al. published in Andrology reviewed global testosterone reference ranges and found significant variation in how labs even measure testosterone, making direct country-to-country comparisons unreliable. Italy appearing on a lowest-testosterone list is harder to support with peer-reviewed data. The claim about Italy is the weakest link in this video's premise.
What did they get wrong (or right)?
They got the directional signal roughly right for Japan and South Korea. East Asian populations do appear in some research to have lower average testosterone levels than Western European or North American populations, though the effect sizes are not dramatic and the methodology varies widely between studies.
What they got badly wrong is the reasoning. Saying South Korea is low testosterone "that's why they are small" conflates two separate biological variables and leans on a stereotype that has no clean scientific basis. Body height and serum testosterone are influenced by overlapping but distinct factors, including nutrition, genetics, and childhood growth hormone secretion. Using one to explain the other is reductive and inaccurate.
Italy as number four is the claim most lacking in evidence. Mediterranean diet patterns, which are common in Italy, are not associated with suppressed testosterone. Some research, including work by Esposito et al. (2006, JAMA Internal Medicine), links Mediterranean dietary patterns to better hormonal and metabolic health outcomes, not worse ones.
The "more testosterone equals more people" logic the creators used for India and Pakistan is also biologically backwards. Population size is driven by fertility rates, cultural factors, and historical context, not testosterone levels.
What should you actually know?
Population-level testosterone comparisons are real research, but they are not as clean as a ranked list suggests. Several factors confound any direct comparison across countries: the time of blood draw, the assay used, the age distribution of the sample, BMI, smoking rates, alcohol consumption, sleep quality, and environmental exposures like endocrine-disrupting chemicals.
Declining testosterone is a documented trend across multiple countries. A 2020 study by Lokeshwar et al. in the European Urology journal confirmed a secular decline in testosterone levels in American men independent of age. Similar trends have been identified in Denmark (Andersson et al., 2007, Journal of Clinical Endocrinology and Metabolism) and in parts of East Asia.
If you are concerned about your own testosterone levels, a country-of-origin ranking is not a useful data point. Age, lifestyle, body composition, sleep, and underlying medical conditions are far stronger predictors of where your levels actually land. A serum total testosterone test ordered by a licensed clinician is the starting point, not a viral Instagram video.
- Do not use videos like this to self-diagnose low testosterone.
- Population averages tell you nothing about your individual biology.
- If symptoms like fatigue, low libido, or mood changes concern you, get tested.