Shares of Mithra Pharmaceuticals (ASX:MITRA) plummeted over 12% following the release of disappointing H1 results and an outlook reduction for its contraceptive drug, Estelle.

The Belgium-based pharmaceutical firm announced weak sales guidance adjustments for Estelle, reflecting marketing partners' inventory and promotional pricing effects.

The pharmaceutical company’s H1 revenues fell 38% year-on-year to 7 million euros, leading to a broadened net loss of 50.5 million euros.

The anticipated annual revenue for Estelle has been marked down to 8.5 million from the previous 12 million euros.

Despite a rise in dispensed Estelle cycles in the U.S., supply sales to Mayne (ASX:MYX) are yet to fully reflect this due to initial inventory buildup and lower promotional pricing, according to KBC.

Further compounding the bleak financial position, Mithra’s stock has nosedived 46% YTD, inclusive of today’s decline.

Mithra Pharmaceuticals (ASX:MITRA) is a Belgium-based firm specializing in the provision of various pharmaceutical solutions.