NEW YORK (AP) — Federal regulators are warning consumers that now-recalled lots of the Tydemy birth control pill “may have reduced effectiveness” due to decreased levels of a key ingredient of the product.

Lupin Pharmaceuticals, which manufactures Tydemy, notified customers on Saturday that it was voluntarily recalling two batches of the oral contraceptive — after one lot tested low for ascorbic acid. Inadequate ascorbic acid “could potentially impact the effectiveness” of the birth control, Lupin said in a company announcement published by the Food and Drug Administration, which could result in unexpected pregnancy.

Even though the recall impacts just two batches of one brand, it’s important for people using birth control to check their stock and contact a health care provider if needed.