From 25 May 1801, her armament was upgraded to carry between 80 and 86 guns. During the Atlantic campaign of 1806, she was the flagship of L'Hermite's squadron (also comprising frigates Président and Cybèle and corvette Surveillant) during L'Hermite's expedition. She patrolled from the Gulf of Guinea to Brazil and the Caribbean. On 6 January 1806 the French squadron captured the 16-gun sloop of war HMS Favourite. The squadron also captured about 20 merchantman, notably including the ships Otway and Plowers. In 1808, Régulus was in station with the Brest squadron.