I think there’s some weak evidence that yes. In some studies where they give HGH for other reasons (a variety of developmental disorders, as well as cases when the child is unusually small or short), an IQ increase or other improved cognitive outcomes are observed. The fact that this occurs in a wide variety of situations indicates that it could be a general effect that could apply to healthy children.
Examples of studies (caveat: produced with the help of ChatGPT, I’m including null results also). Left column bolded when there’s a clear cognitive outcome improvement.
Treatment group
Observed cognitive / IQ effects of HGH
Study link
Children with isolated growth hormone deficiency; repeated head circumference and IQ testing during therapy
IQ increased in parallel with head-size catch-up (small case series, N=4). Exact IQ‐point gains not reported in the abstract.
Short-stature children (growth hormone deficiency and idiopathic short stature), ages 5–16, followed 3 years during therapy
IQ and achievement scores: no change over 3 years (≈0 IQ-point mean change reported); behavior improved (e.g., total problems ↓, P<.001 in growth hormone deficiency; attention/social/thought problems each P=.001).
Children born small for gestational age, long-term randomized dose-response cohort (≈8 years of therapy)
Total IQ and “performal” IQ increased from below population norms to within normal range by follow-up (p<0.001). Precise IQ-point means not in abstract.
Children born small for gestational age, randomized, double-blind dose-response trial (1 vs 2 mg/m²/day)
Total IQ and Block-Design (performance) scores increased (p<0.001). Head-size growth correlated positively with all IQ scores; untreated controls did not show head-size increases. Exact IQ-point changes not in abstract.
Prepubertal short children (mix of growth hormone deficiency and idiopathic short stature), randomized to fixed vs individualized dosing for 24 months
Full-scale IQ increased with a medium effect size (Cohen’s d ≈0.6) after 24 months; processing speed also improved (d ≈0.4). Exact IQ-point means not provided in abstract.
Children born small for gestational age, randomized to high-dose growth hormone for 2 years vs no treatment
No cognitive benefit over 2 years: IQ unchanged in the treated group; in the untreated group, mean IQ rose (P<.05), but after excluding children with developmental problems, neither group changed significantly. Behavioral checklist scores: no significant change.
Prepubertal children with Prader–Willi syndrome, randomized controlled trial (2 years) plus 4-year longitudinal follow-up on therapy
Prevents decline seen in untreated controls (vocabulary and similarities declined in controls at 2 years, P=.03–.04). Over 4 years on therapy: abstract reasoning (Similarities) and visuospatial skills (Block Design) increased (P=.01 and P=.03). Total IQ stayed stable on therapy vs decline in controls.
Infants and young children with Prader–Willi syndrome (approximately 52-week therapy; earlier vs later start)
Mental development improved after 52 weeks; earlier initiation (<9 months) associated with greater mental-development gains than later start. Exact test scores vary by age tool; abstract does not list points.
Down syndrome cohort, ~15-year follow-up after early childhood growth hormone
No advantage in brief IQ scores at long-term follow-up; higher scores in multiple cognitive subtests (e.g., Leiter-R, WISC-III subtests) vs controls; larger adult head circumference in previously treated group.
I would also suggest looking at IGF-1. You can reach out to me; this topic interests me and I have a lot of experience working with HGH and IGF-1 (including a world record).
Could HGH supplementation in children improve IQ?
I think there’s some weak evidence that yes. In some studies where they give HGH for other reasons (a variety of developmental disorders, as well as cases when the child is unusually small or short), an IQ increase or other improved cognitive outcomes are observed. The fact that this occurs in a wide variety of situations indicates that it could be a general effect that could apply to healthy children.
Examples of studies (caveat: produced with the help of ChatGPT, I’m including null results also). Left column bolded when there’s a clear cognitive outcome improvement.
I would also suggest looking at IGF-1. You can reach out to me; this topic interests me and I have a lot of experience working with HGH and IGF-1 (including a world record).
https://pubmed.ncbi.nlm.nih.gov/16263982/
has it been tested on adults a lot?