A 2024 rodent study investigated sulforaphane’s effects on skeletal muscle:

“Sulforaphane (SFN) shows a promising application in skeletal muscle protection and recovery from muscle atrophy and damage. However, limited work has focused on the role of SFN in maintaining the balance of protein and lipid metabolism in skeletal muscle.

The current work investigates effects of SFN at an everyday consumption level on protein and lipid metabolism in skeletal muscle. Investigating SFN at lower levels over an extended period more closely resembles human consumption habits. Four-week-old mice received SFN at a dosage of 1 mg per kilogram of body weight per day (1 mg/kg/d BW) using i.p. injection (SFN1 group) and 3 mg/kg/d BW (SFN3 group) for eight weeks, equivalent to concentrations of 0.14 μM and 0.42 μM.

Histological analysis was performed for the Longissimus dorsi [the largest back muscle]. LD muscle fiber diameter and cross-section area was significantly increased in the SFN3 group, not in the SFN1 group.

The levels of triglycerides and total cholesterol in the LD muscle were found to be decreased in both SFN groups.

This study reported, for the first time, that SFN administration increased peroxisome activity and enhanced the peroxisomal protein shuttle, which supports enhanced peroxisomal fatty acid β-oxidation. SFN redirects the flux of fatty acid to be utilized through β-oxidation in peroxisomes and mitochondria to support muscle growth. Furthermore, SFN treatment influenced lipid and protein metabolism related pathways including AMPK signalling, fatty acid metabolism signalling, cholesterol metabolism signalling, PPAR signalling, peroxisome signalling, TGFβ signalling, and mTOR signalling.”

https://portlandpress.com/bioscirep/article/doi/10.1042/BSR20240084/234562/Sulforaphane-enhanced-muscle-growth-by-promoting “Sulforaphane enhanced muscle growth by promoting lipid oxidation through modulating key signaling pathways”

A human equivalent to this study’s 3 mg daily dose is (3 mg x .081) x 70 kg = 17 mg, albeit doses were intraperitoneally injected. An oral 17 mg is a common sulforaphane floor dose in human studies, and is approximately what I get from eating 60 grams of a microwaved broccoli / red cabbage / mustard 3-day-old sprouts mix daily.