Background/Objectives: Lavender has been utilized for its medicinal properties since ancient times, with numerous health benefits reported. This study aimed to valorize solid waste from lavender essential oil production by developing a novel lavender extract from solid lavender residues. The extract’s preclinical safety and efficacy were evaluated with emphasis on plasma lipid and lipoprotein metabolism, glucose tolerance, and adipose tissue metabolic activity. Methods: Male C57BL/6 mice were divided into four groups of five mice each and fed for 30 days with lavender extract encapsulated in 10% maltodextrin, mixed with a standard chow diet. The first group (Lav 1×) received 21.1 mg/kg/day, the second group (Lav 10×) received 211 mg/kg/day, and the third group (Lav 100×) received 2110 mg/kg/day. A placebo group consumed the standard diet without lavender extract. Key outcomes included plasma lipid and lipoprotein profiles, transaminase levels, HDL antioxidant and anti-inflammatory potential, glucose tolerance, and mitochondrial activity in white (WAT) and brown (BAT) adipose tissues. Results: The novel lavender extract induced dose-dependent improvements in lipid and lipoprotein metabolism, glucose tolerance, and adipose tissue activity. The 2110 mg/kg dose (100×) demonstrated the most significant beneficial effects, although it was associated with a slight elevation in hepatic transaminase levels, indicating potential mild hepatic stress. Conclusions: Overall, the novel lavender extract exhibits promising health benefits with no major safety concerns at the tested doses, supporting its potential for therapeutic applications.