In the quantitative analysis of animal studies, ginger improved liver levels of the following:

Ginger also improved serum levels of the following:

ALT (−2.85 U/L)
AST (−0.98 U/L)
Catalase (+3.35 nmol/mg),
Fasting blood sugar (−2.53 mg/dL)
HDL-C (+1.27 mg/dL)
LDL-C (−3.94 mg/dL)
Malondialdehyde (−3.16 nmol/L)
Superoxide dismutase (+3.01 U/mg),
Triglycerides (−4.98 mg/dL)
Total cholesterol (−3.35 mg/dL)

The qualitative analysis of 3 clinical trials in humans found the following:

In a 2016 randomized controlled trial, 44 patients with nonalcoholic fatty liver disease (NAFLD) consumed 2 grams per day of ginger or a placebo for 12 weeks. Ginger reduced serum ALT and gamma-glutamyl transferase levels (another marker of liver health) compared to placebo. There was no effect of ginger on liver fibrosis or AST.^[1]
In a 2020 randomized controlled trial, 46 patients with NAFLD were randomized to take 1.5 grams of ginger per day or a placebo for 12 weeks. Serum levels of ALT, total cholesterol, LDL-C, fasting blood sugar, HOMA-IR, C-reactive protein, and fetuin-A were lower in the ginger group than the placebo group. There were no differences between the two groups in body weight, fasting insulin, HDL-C, triglycerides, gamma-glutamyl transferase, AST, adiponectin, TNF-α, total antioxidant capacity, hepatic steatosis, or blood pressure.^[2]
In a 2021 randomized controlled trial, 46 active men were randomized to i) take 3 grams per day of ginger and perform high-intensity interval training (HIIT), ii) take 3 grams of ginger without performing HIIT, iii) perform HIIT without taking ginger, or iv) take neither ginger nor perform HIIT for 4 weeks. The group that took ginger and performed HIIT had greater improvements in HOMA-IR, ALT, AST, blood glucose, insulin, body weight, waist circumference, and BMI than the other groups^[3]

Ginger and liver health Original paper