Component

Circulating free testosterone concentration

Circulating free testosterone concentration. Species, exposure and limitations are retained in each linked claim.

5 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What acts on it

  1. Mean free testosterone increased at the one-week morning measurement in the eight-man supplementation study.

    Boron → Circulating free testosterone concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/boron-research/21129941.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4e5892df5d6f2cf5e87f6bd3c7c12dae16cc2fa2517d5a81267b810175485157", "start_char": 0, "end_char": 1706, "text_sha256": "4e5892df5d6f2cf5e87f6bd3c7c12dae16cc2fa2517d5a81267b810175485157"}
    experimental_model
    Sequential placebo-day and supplementation observations in eight men
    exposure
    10 mg boron/day for one week; acute six-hour and day-seven measurements
    limitations
    Eight participants without a randomized parallel control. Time effects, short duration and multiple endpoints limit causal and clinical interpretation. Lower SHBG does not demonstrate direct boron binding to SHBG.
    nutrient_topic
    Boron research collection; topical membership is not evidence of a direct dietary effect. · Boron
    organism
    Human healthy male volunteers
    plain_language
    A short uncontrolled comparison reported a rise in free testosterone; it is not reliable evidence of a general testosterone-boosting effect.
    primary_references
    [boron-p21129941] Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines. (2011). https://pubmed.ncbi.nlm.nih.gov/21129941/ DOI: 10.1016/j.jtemb.2010.10.001
    tissue_or_cell_type
    Plasma hormones and inflammatory biomarkers

    Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (2026-09-17) · lines 1015–1026

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Sequential placebo-day and supplementation observations in eight men · source_derived_draft · unverified_draft

    ### boron-short-study-free-testosterone Mean free testosterone increased at the one-week morning measurement in the eight-man supplementation study. Condition category: normal nutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect. plain_language: A short uncontrolled comparison reported a rise in free testosterone; it is not reliable evidence of a general testosterone-boosting effect. organism: Human healthy male volunteers tissue_or_cell_type: Plasma hormones and inflammatory biomarkers experimental_model: Sequential placebo-day and supplementation observations in eight men limitations: Eight participants without a randomized parallel control. Time effects, short duration and multiple endpoints limit causal and clinical interpretation. Lower SHBG does not demonstrate direct boron binding to SHBG. exposure: 10 mg boron/day for one week; acute six-hour and day-seven measurements evidence_span: {"source_cache": "artifacts/boron-research/21129941.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "4e5892df5d6f2cf5e87f6bd3c7c12dae16cc2fa2517d5a81267b810175485157", "start_char": 0, "end_char": 1706, "text_sha256": "4e5892df5d6f2cf5e87f6bd3c7c12dae16cc2fa2517d5a81267b810175485157"} [boron-p21129941] Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines. (2011). https://pubmed.ncbi.nlm.nih.gov/21129941/ DOI: 10.1016/j.jtemb.2010.10.001
    Complete structured claim and evidence

  2. The reduction in free testosterone differed from placebo in the small D-chiro-inositol trial (P=0.006).

    D-chiro-inositol → Circulating free testosterone concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/inositol-research/10219066.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2b70007c28cc93c6f18b457701ec8b034a3bbe888db05e85eca71d50199dc854", "start_char": 0, "end_char": 2121, "text_sha256": "2b70007c28cc93c6f18b457701ec8b034a3bbe888db05e85eca71d50199dc854"}
    experimental_model
    Randomized placebo-controlled trial
    exposure
    D-chiro-inositol 1200 mg/day for 6–8 weeks versus placebo; historical study regimen
    limitations
    Small short trial, not live-birth evidence. Within-group insulin improvement was stronger than the between-group comparison.
    nutrient_topic
    Inositol research collection; topical membership is not evidence of a direct dietary effect. · Inositol (stereoisomer family)
    organism
    Homo sapiens
    plain_language
    One androgen measure improved in this specific study.
    primary_references
    [ino-p10219066] Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome. (1999). https://pubmed.ncbi.nlm.nih.gov/10219066/ DOI: 10.1056/nejm199904293401703
    tissue_or_cell_type
    44 obese women with PCOS

    Inositol: synthesis, signaling, mineral interactions and conditional deficiency (2026-09-17) · lines 1315–1326

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized placebo-controlled trial · source_derived_draft · unverified_draft

    ### ino-dci-testosterone The reduction in free testosterone differed from placebo in the small D-chiro-inositol trial (P=0.006). Condition category: normal nutrient_topic: Inositol research collection; topical membership is not evidence of a direct dietary effect. plain_language: One androgen measure improved in this specific study. organism: Homo sapiens tissue_or_cell_type: 44 obese women with PCOS experimental_model: Randomized placebo-controlled trial limitations: Small short trial, not live-birth evidence. Within-group insulin improvement was stronger than the between-group comparison. exposure: D-chiro-inositol 1200 mg/day for 6–8 weeks versus placebo; historical study regimen evidence_span: {"source_cache": "artifacts/inositol-research/10219066.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "2b70007c28cc93c6f18b457701ec8b034a3bbe888db05e85eca71d50199dc854", "start_char": 0, "end_char": 2121, "text_sha256": "2b70007c28cc93c6f18b457701ec8b034a3bbe888db05e85eca71d50199dc854"} [ino-p10219066] Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome. (1999). https://pubmed.ncbi.nlm.nih.gov/10219066/ DOI: 10.1056/nejm199904293401703
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Boron supplementation did not significantly improve total or free testosterone relative to placebo in the seven-week bodybuilding study.

    Boron → Circulating total testosterone concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/boron-research/8508192.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91f7c44f1eb8036fa77ee50cc2cc993c8fcf0bd65f26752b1c9d6d504db34770", "start_char": 0, "end_char": 1032, "text_sha256": "91f7c44f1eb8036fa77ee50cc2cc993c8fcf0bd65f26752b1c9d6d504db34770"}
    experimental_model
    Placebo-controlled supplementation trial; 19 male bodybuilders aged 20–27
    exposure
    Ten participants received 2.5 mg boron/day and nine placebo for seven weeks
    limitations
    Small trial in a training context; null results do not prove absence of effects at all doses or in all populations. Training-related improvement in both groups was not a boron effect.
    nutrient_topic
    Boron research collection; topical membership is not evidence of a direct dietary effect. · Boron
    organism
    Human
    plain_language
    This controlled study did not find a testosterone benefit.
    primary_references
    [boron-p8508192] The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders. (1993). https://pubmed.ncbi.nlm.nih.gov/8508192/ DOI: 10.1123/ijsn.3.2.140
    tissue_or_cell_type
    Hormone, lean-mass and strength outcomes

    Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (2026-09-17) · lines 976–987

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Placebo-controlled supplementation trial; 19 male bodybuilders aged 20–27 · source_derived_draft · unverified_draft

    ### boron-bodybuilding-testosterone-null Boron supplementation did not significantly improve total or free testosterone relative to placebo in the seven-week bodybuilding study. Condition category: normal nutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect. plain_language: This controlled study did not find a testosterone benefit. organism: Human tissue_or_cell_type: Hormone, lean-mass and strength outcomes experimental_model: Placebo-controlled supplementation trial; 19 male bodybuilders aged 20–27 limitations: Small trial in a training context; null results do not prove absence of effects at all doses or in all populations. Training-related improvement in both groups was not a boron effect. exposure: Ten participants received 2.5 mg boron/day and nine placebo for seven weeks evidence_span: {"source_cache": "artifacts/boron-research/8508192.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "91f7c44f1eb8036fa77ee50cc2cc993c8fcf0bd65f26752b1c9d6d504db34770", "start_char": 0, "end_char": 1032, "text_sha256": "91f7c44f1eb8036fa77ee50cc2cc993c8fcf0bd65f26752b1c9d6d504db34770"} [boron-p8508192] The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders. (1993). https://pubmed.ncbi.nlm.nih.gov/8508192/ DOI: 10.1123/ijsn.3.2.140
    Complete structured claim and evidence

  2. In a 24-man resistance-trained trial, 3 g/day for 14 days did not change testosterone; 6 g/day lowered total and calculated free testosterone.

    D-Aspartate → Circulating total testosterone concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text
    experimental_model
    Eight men per placebo, 3 g and 6 g arm; at least two years of resistance training.
    limitations
    Small groups and short duration; calculated free testosterone is not a direct free-hormone assay.
    nutrient_topic
    D-Aspartate collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · D-Aspartate
    plain_language
    More was not better in this short dose-comparison trial.
    primary_references
    Three and six grams supplementation of d-aspartic acid in resistance trained men. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25844073/ · DOI 10.1186/s12970-015-0078-7

    D-Aspartate: synthesis, clearance, neural and endocrine mechanisms (2026-09-19) · lines 344–350

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Eight men per placebo, 3 g and 6 g arm; at least two years of resistance training. · source_derived_draft · unverified_draft

    ## d-aspartate-human-dose-trial More was not better in this short dose-comparison trial. In a 24-man resistance-trained trial, 3 g/day for 14 days did not change testosterone; 6 g/day lowered total and calculated free testosterone. Model: Eight men per placebo, 3 g and 6 g arm; at least two years of resistance training. Limitations: Small groups and short duration; calculated free testosterone is not a direct free-hormone assay. Evidence access: Primary full text Three and six grams supplementation of d-aspartic acid in resistance trained men. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25844073/ · DOI 10.1186/s12970-015-0078-7
    Complete structured claim and evidence

  3. A 12-week 6 g/day trial in trained men found no testosterone benefit or added strength/hypertrophy benefit over placebo.

    D-Aspartate → Circulating total testosterone concentration source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary full text
    experimental_model
    22 randomized, 19 completed; resistance training four days weekly.
    limitations
    Overlapping investigators with the 2015 trial; not independent laboratory replication. Hormonal and training endpoints are distinct.
    nutrient_topic
    D-Aspartate collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · D-Aspartate
    plain_language
    The longer higher-dose trial also failed to show a testosterone advantage.
    primary_references
    The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial. · 2017 · https://pubmed.ncbi.nlm.nih.gov/28841667/ · DOI 10.1371/journal.pone.0182630

    D-Aspartate: synthesis, clearance, neural and endocrine mechanisms (2026-09-19) · lines 352–358

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · 22 randomized, 19 completed; resistance training four days weekly. · source_derived_draft · unverified_draft

    ## d-aspartate-human-longer-trial The longer higher-dose trial also failed to show a testosterone advantage. A 12-week 6 g/day trial in trained men found no testosterone benefit or added strength/hypertrophy benefit over placebo. Model: 22 randomized, 19 completed; resistance training four days weekly. Limitations: Overlapping investigators with the 2015 trial; not independent laboratory replication. Hormonal and training endpoints are distinct. Evidence access: Primary full text The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial. · 2017 · https://pubmed.ncbi.nlm.nih.gov/28841667/ · DOI 10.1371/journal.pone.0182630
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

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