critpanda
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Isotretinoin is a Vitamin A derivate and a retinoid ( Vitamin A analogue ).
Vitamin A analogues are known to affect your bone and cartilage metabolism, and several case reports and series have documented premature epiphyseal closure in patients treated with iso or related retinoids. In isolated adolescent cases, patients on acne-dose isotretinoin developed growth arrest and fused growth plates, most often in the knee. For example, a 15-year-old boy on isotretinoin (~1 mg/kg/day for 4.5 months) stopped growing.
Similarly, a 16-year-old on ~0.5–0.75 mg/kg/day for 6 months developed knee pain; MRI and imaging showed irregularity and ossification of the growth plate (epiphysiodesis) in femur and tibia.
The FDA has received dozens of reports: one review found 41 global cases of isotretinoin-linked epiphyseal closure in patients <18 years, in that survey, 9 reported cases ranged from 0.5 mg/kg/day (few months) to 3.5 mg/kg/day (years)
Beyond case reports, epidemiologic data are sparse. A recent large retrospective cohort presented at AAD 2024 compared adult height in ~11,000 acne patients treated with isotretinoin (<=18 years old) vs. ~35,000 treated with doxycycline. On average, there was no reduction in adult height among isotretinoin users; in fact, the isotretinoin group was slightly taller than the control group. The authors concluded there was “evidence against an association between isotretinoin and premature epiphyseal closure” in pediatric acne patients
No prospective longitudinal trials have specifically followed growth rates during acne therapy. One small cross-sectional study (n≈30) reported on pediatric gh levels during iso: GH and IGF-1 levels were unchanged. A rat study found high-dose all-trans RA (10 days) markedly reduced circulating GH, IGF-I, and IGFBP-3; these rats had shorter bones, narrowed growth plates, and early bone marrow mineralization
Leachman et al. (1999) - A controlled study of young adult males (17–25 y) on isotretinoin (1 mg/kg for 6 months) vs untreated controls found a modest but significant bone density loss at the hip. Four of 28 treated men lost >9% at the hip. The authors warned this small loss, although modest, hinted at retinoid-induced osteoporosis requiring further study.
Acitretin (etretinate): Used in psoriasis, it is a potent retinoid with bone effects. In rats, high-dose acitretin over weeks caused degenerative changes in the growth platew Onder et al. (2020) gave juvenile rats 3–10 mg/kg/day acitretin for 4 weeks; histology showed epiphyseal degeneration and reduced plate thickness (though differences were not always statistically significant. This confirms that systemic retinoids can disturb growth cartilage. In humans, long-term acitretin is known to cause diffuse skeletal hyperostosis (excess bone growth) and bridging in adults, underscoring its strong effect on bone remodeling.
It seems the overall risk is a highly rare spontaneous closure - read the studies and come to your own conclusion.
Vitamin A analogues are known to affect your bone and cartilage metabolism, and several case reports and series have documented premature epiphyseal closure in patients treated with iso or related retinoids. In isolated adolescent cases, patients on acne-dose isotretinoin developed growth arrest and fused growth plates, most often in the knee. For example, a 15-year-old boy on isotretinoin (~1 mg/kg/day for 4.5 months) stopped growing.
Similarly, a 16-year-old on ~0.5–0.75 mg/kg/day for 6 months developed knee pain; MRI and imaging showed irregularity and ossification of the growth plate (epiphysiodesis) in femur and tibia.
The FDA has received dozens of reports: one review found 41 global cases of isotretinoin-linked epiphyseal closure in patients <18 years, in that survey, 9 reported cases ranged from 0.5 mg/kg/day (few months) to 3.5 mg/kg/day (years)
| Reference | Age/Sex | Isotretinoin Dose & Duration | Findings |
|---|---|---|---|
| Tran et al. (2007) (poster) | 15/M | ~1 mg/kg/day for 4.5 months | Cessation of growth; knee X-ray showed fused distal femur/proximal tibia plates. |
| Luthi et al. (2012) | 16/M | ~6 months (0.5–0.75 mg/kg/day) | MRI: irregular knee growth plates with edema; diagnosed retinoid‐induced epiphysiodesis. Symptoms (knee pain) resolved after stopping drug, though a thumbprint lesion remained. |
| Delgado et al. (2023) (NB survivors) | 9–16 (NB survivors) | 6.5–7.6 years (cumulative ∼8500 mg) | Pediatric cancer context: On MRI, 3/20 had physeal bony bridges and 9/20 metaphyseal tongues; associated with short stature. (All treated with high-dose isotretinoin plus chemo/radiation.) |
| Multiple case series | – | variable (often high-dose) | Neuroblastoma series found ~1.4% incidence of growth plate arrest (3/216 patients); others reported knee valgus deformities from asymmetric plate fusion. |
Beyond case reports, epidemiologic data are sparse. A recent large retrospective cohort presented at AAD 2024 compared adult height in ~11,000 acne patients treated with isotretinoin (<=18 years old) vs. ~35,000 treated with doxycycline. On average, there was no reduction in adult height among isotretinoin users; in fact, the isotretinoin group was slightly taller than the control group. The authors concluded there was “evidence against an association between isotretinoin and premature epiphyseal closure” in pediatric acne patients
No prospective longitudinal trials have specifically followed growth rates during acne therapy. One small cross-sectional study (n≈30) reported on pediatric gh levels during iso: GH and IGF-1 levels were unchanged. A rat study found high-dose all-trans RA (10 days) markedly reduced circulating GH, IGF-I, and IGFBP-3; these rats had shorter bones, narrowed growth plates, and early bone marrow mineralization
Leachman et al. (1999) - A controlled study of young adult males (17–25 y) on isotretinoin (1 mg/kg for 6 months) vs untreated controls found a modest but significant bone density loss at the hip. Four of 28 treated men lost >9% at the hip. The authors warned this small loss, although modest, hinted at retinoid-induced osteoporosis requiring further study.
Acitretin (etretinate): Used in psoriasis, it is a potent retinoid with bone effects. In rats, high-dose acitretin over weeks caused degenerative changes in the growth platew Onder et al. (2020) gave juvenile rats 3–10 mg/kg/day acitretin for 4 weeks; histology showed epiphyseal degeneration and reduced plate thickness (though differences were not always statistically significant. This confirms that systemic retinoids can disturb growth cartilage. In humans, long-term acitretin is known to cause diffuse skeletal hyperostosis (excess bone growth) and bridging in adults, underscoring its strong effect on bone remodeling.
It seems the overall risk is a highly rare spontaneous closure - read the studies and come to your own conclusion.
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