They can be, depends on many factors and your metabolic markers.
Personally having read and researched extensively I would not take them unless I'd had a heart attack, stroke etc.... But remember I am not a doctor.
Research easily found from a quick Google search will point you to numerous side effects including but not limited to:
- diabetes
- cardio vascular
- kidney prob
- liver probs
- cramps
Etc
Diagnosed 13/4/16: T2, no meds, HbA1c 53, FBG 12.6, Trigs 3.6, HDL .75, LDL 4.0, BP 169/95, 13st 8lbs, waist 34" (2012 - 17st 7lbs, w 42").
6/6/16: FBG AV 4.6, Trigs 1.5, HDL 2.0, LDL 3.0, BP 112/68, BPM 66, 11st 11lbs, waist 30".
Regime: 20g LCHF, run 1 mile daily, weekly fasting.