Leptin
Leptin is a hormone produced by fat cells that helps regulate appetite and energy balance by signaling the brain when you have enough stored fat. This test measures the level of leptin in your blood.
Category: Diabetes & Glycemic
Also known as: leptin, serum leptin, ob protein
Reference range: 2–5.6 ng/mL (Source: ABIM)
Standard unit: ng/mL
High values may indicate
High leptin levels may indicate leptin resistance (common in obesity), where the brain does not respond properly to leptin signals, leading to continued overeating and weight gain.
Low values may indicate
Low leptin levels may indicate lipodystrophy (loss of body fat), severe caloric restriction, or genetic leptin deficiency, which can cause extreme hunger and early-onset obesity.
Frequently asked questions
- What is a normal Leptin level?
- A typical reference range for Leptin is 2–5.6 ng/mL (source: ABIM). Reference ranges vary by laboratory, age, and sex, so always compare against the range on your own lab report.
- What units is Leptin measured in?
- Leptin is most commonly reported in ng/mL. Labs in different countries may use other units — you can convert between them with BloodId's blood test unit converter.
- Where do Leptin reference ranges come from?
- BloodId uses ABIM standard reference ranges and educational information from MedlinePlus (see our methodology). Reference ranges still vary by lab, age, and sex, so always compare against your own report.
- Can I track Leptin over time?
- Yes. Upload results from any lab and BloodId charts your Leptin over time against its reference range, so you can see whether the trend is rising, falling, or stable.