Should the theory of methotrexate-induced liver toxicity be abandoned?

Methotrexate (MTX) remains a cornerstone therapy for chronic inflammatory diseases (e.g., rheumatoid arthritis, psoriasis). However, long-standing concerns about MTX hepatotoxicity - especially liver fibrosis - have historically led to conservative monitoring and routine invasive liver biopsies at predefined cumulative dose thresholds. These practices often prompted early discontinuation of MTX therapy. These concerns originated from early liver biopsy studies in high-dose MTX patients that did not adequately account for metabolic risk factors. Emerging evidence indicates that advanced fibrosis is rare in MTX-treated patients and usually attributable to coexisting metabolic comorbidities (e.g., obesity, insulin resistance) rather than the cumulative MTX dose itself. Moreover, noninvasive fibrosis assessment modalities and recent large cohort studies demonstrate that MTX at standard doses with folate supplementation seldom drives fibrogenesis independently. This review reappraises MTX-related fibrosis risk in light of contemporary data and highlights a shift from dose-driven biopsy protocols to risk-based, noninvasive monitoring strategies. Recognizing that MTX is less hepatotoxic than historically assumed can prevent unnecessary drug discontinuation and refocus management on modifiable metabolic risk factors.