D-Aspartic Acid and testosterone

What 6 graded rows on d-aspartic acid agree on for testosterone, and where they differ. Counted side by side, never averaged.

Consensus finder Rows from the D-Aspartic Acid page, reviewed Oct 21, 2026 How it decides

What the rows agree on

Each block and row is one graded row from the D-Aspartic Acid page, with its PubMed record.

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D-Aspartic Acid and testosterone

6 rows · 138 people

Mostly no difference: 4 of 6 rows, and most of the people. 1 found an improvement and 1 found a worse outcome.

No difference or worse

Improved

Each block is one evidence row, sized by how many people it enrolled, with its grade inside. Red: a worse outcome.

Grade D× 6

Rows: 6
Trials: 6
People: 138

Where they differ

From the rows

Trial sizeHow longWho was studiedWhen published

The best-graded row, grade D, is an open-label trial of 43 people (2009) and found an improvement.

The row that found an improvement was larger: 43 people, against a median of 18 people for the 4 rows that found no difference.

The 4 rows that found no difference ran longer (2 weeks to 3 months) than the row that found an improvement (12 days).

Only the 4 rows that found no difference name athletes or trained people in their population.

The 4 rows that found no difference are newer (2013 to 2023) than the row that found an improvement (2009).

The rows

1 improved · 4 no difference · 1 worse

Grade DTestosterone, LH and strength in resistance-trained men · No difference
RCT · n 20 · 2013 · Resistance-trained men during 28 days of heavy training (USA)
3 g/day · 28 days
Total and free testosterone, LH, GnRH and estradiol did not change; strength and body composition improved equally with placebo.
Row on the D-Aspartic Acid page · PubMed 24074738 (opens PubMed)
Grade DTestosterone, strength and muscle size over 12 weeks of training · No difference
RCT · n 19 · 2017 · Resistance-trained men aged 18–36 (Australia)
6 g/day · 12 weeks
No change in total or free testosterone. Estradiol fell 16% with D-aspartic acid. Strength and muscle growth increased similarly in both groups.
Row on the D-Aspartic Acid page · PubMed 28841667 (opens PubMed)
Grade DTestosterone, cortisol and blood counts in boxers at simulated altitude · No difference
RCT · n 16 · 2023 · Male boxers sleeping in normobaric hypoxia (Poland)
6 g/day · 14 days
No significant effect on resting testosterone, LH or the testosterone/cortisol ratio, and no added effect on red blood cell changes.
Row on the D-Aspartic Acid page · PubMed 38201906 (opens PubMed)
Grade DTestosterone, LH and physical function in male climbers · No difference
Crossover RCT · n 16 · 2019 · Male climbers continuing normal training (Poland)
3 g/day · 2 weeks per arm
Serum testosterone, calculated free testosterone and LH did not change versus placebo; physical function and hematology also did not respond.
Row on the D-Aspartic Acid page · PubMed 29893592 (opens PubMed)
Grade DSerum testosterone and LH in healthy untrained men · Improved
Open-label trial · n 43 · 2009 · Healthy men aged 27–37 at an IVF unit (Italy)
3.12 g/day sodium D-aspartate · 12 days
Testosterone rose from 4.5 to 6.4 ng/mL (about 42%) and LH by about 33% in the D-aspartate group; the placebo group did not change.
Row on the D-Aspartic Acid page · PubMed 19860889 (opens PubMed)
Grade DTotal and free testosterone in resistance-trained men (3 g vs 6 g) · Worse
RCT · n 24 · 2015 · Men with at least two years of resistance training (Australia)
3 g/day or 6 g/day vs 6 g/day flour placebo · 14 days
3 g/day had no effect on testosterone. 6 g/day lowered total testosterone and lowered free testosterone compared with placebo (P=0.005).
Row on the D-Aspartic Acid page · PubMed 25844073 (opens PubMed)

Read onRead the full evidenceThe full evidence chapter on its page, with every outcome and its sources.