This capsule delivers 400 mg of whole **lemon peel** (Citrus limon), a natural source of **d-limonene** — a monoterpene found in citrus rinds. D-limonene has been studied for occasional heartburn relief, but the clinical evidence is limited to two very small trials (13 and 19 participants), both funded by a patent holder. No large-scale human studies or meta-analyses exist to confirm those results.

The main issue for your results is dosage. Whole lemon peel contains roughly 5-10% d-limonene by weight, which means your 400 mg serving provides an estimated 20-40 mg of the active compound. Clinical studies on d-limonene used 500-1000 mg of the pure form — putting this product well below the range where any effect was observed. If your goal is digestive comfort through d-limonene, 400 mg of whole peel falls well short of what the limited research has tested.

Antioxidant and anti-inflammatory properties attributed to citrus peel compounds come from animal and lab studies that have not been validated in human trials. Your other ingredients — gelatin capsule shell, rice flour, magnesium stearate, and silica — are standard capsule components with no active role.