Herbs have been used for centuries to prevent and control many diseases. The biggest challenge and problem is lack of information about the effect of herbs and its side effects. Thyme (thymus vulgaris) is a small shrubby plant with a strong, spicy taste, and odor. Thyme has carminative, diaphoretic, expectorant, sedative, antibacterial and antifungal properties. It also has antispasmodic effects; tea made by infusing the herb in water or thyme juice ready-to-use is traditionally frequently used for infantile colic in our country. A fourteen-day-old male newborn was admitted to the emergency department with severe respiratory distress. There was a history of 50 mL of thyme juice (added table sugar) ingestion given for his infantile colic two hours before admission. He had hypoglycemia, hyperuricemia, and lactic acidosis. Further investigation confirmed fructose 1-6 diphosphatase deficiency in the patient. We thought that lactic acidosis may have been triggered by fructose added to the thyme water to sweeten its taste. However, phenolic compounds of thyme juice may also cause acidosis.