POWO (2025) recognises two subspecies, the nominate subsp. requienii, and subsp. bistaminata Mannocci & Falconcini from the Italian islands of Capraia.

The variety obovata (Gand.) Litard (Corsica) is not recognised by POWO (2025).

This species is endemic to Europe, where it occurs on Corsica (France) and Italy (Sardinia, Capraia, and Montecristo). Mentha requienii has a relatively small range (area of occupancy of less than 500 km²), but the populations are believed to be stable and it is not facing any major threats at present. It is therefore listed as Least Concern.

Mentha requienii is endemic to Italy and France. It Italy, it occurs on the islands of Sardinia, Capraia, and Montecristo. In France it is restricted to Corsica (France). The variety requienii is found in Corsica from the north to the south as well as in Sardinia and Montecristo, the variety obovata (Gand.) Litard is found in Corsica only and is very rare. The extent of occurrence is 38,764 km² and the area of occupancy is less than 500 km².

The species has been introduced in Europe to Portugal and the British Isles. It has been widely introduced out of the European region, especially to the Americas, and it is considered invasive in some countries (POWO 2025).

There are about ten populations in Sardinia (Marras 2000) and they are probably more numerous in Corsica.

Mentha requienii occurs in wet meadows and pozzines.

There are no major anthropogenic threats known at present.

Mentha requienii is an aromatic plant that is also used for ornamental purposes. Medicinal uses are also reported. The species is available in the ornamental plant trade.

No specific conservation measures are known. The species has been assessed as Least Concern for France (UICN France et al. 2018). Monitoring of the populations is recommended.