l-carnitine grams per day Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial Nutricost L-Carnitine Tartrate Supplement Powder

They are both herbal supplements but come from different plants

Metformin (N,N-dimethylbiguanide), a standard clinical drug for type 2 diabetes mellitus (T2DM) for over 60 years (Foretz et al., 2023), has been shown to have multiple biological effects beyond its hypoglycemic properties, such as antioxidant, anti-inflammatory, anti-tumor, anti-fibrotic, and antiviral activities (Du et al., 2022

They can explain whether its appropriate for your case

Villacorta L, Zhang J, Garcia-Barrio MT, Chen XL, Freeman BA, Chen YE, et al

N Engl J Med 357(21):2133-42, 2007

The likelihood of this is significantly higher for those with prior heart conditions