For the JenSkin panel specifically: yes. An 8-12 hour overnight fast is required for accurate results on the metabolic markers, and recommended for the panel as a whole.
Why fasting matters for the JenSkin panel:
- Fasting glucose — must be measured after 8+ hours without food to be interpretable. A recently-eaten meal invalidates the number entirely.
- Fasting insulin — same requirement. Insulin rises after any meal; only fasting values reflect baseline metabolic strain.
- HbA1c — reflects 90-day glucose exposure, so a single meal doesn't affect it. Doesn't require fasting to be accurate, but fasting is standard practice for the panel.
- hs-CRP, vitamin D, B12, zinc, ferritin, omega-3 index, estradiol — don't strictly require fasting, but morning fasted timing gives the most consistent baseline for repeat testing.
The recommended protocol:
- Finish dinner by 8pm the night before your draw
- Water is fine and encouraged (helps with the draw)
- Coffee, tea, gum, mints — all should be avoided until after the draw
- Medications — take as usual unless your physician says otherwise
- Schedule your draw for morning (7-10am) when possible
Estradiol timing note: For premenopausal women still cycling, estradiol should ideally be drawn on cycle day 3-5 for a comparable baseline. Not strictly required — but if you're planning to retest to see changes, keeping the cycle day consistent is more important than fasting for that particular marker.
The panel is designed for one clean fasted draw covering all nine markers. No multiple visits, no different-day scheduling required.