Benefits
Knee comfort and physical quality of life in older adults
In a 12-week placebo-controlled trial, 20 middle-aged and older adults with mild knee discomfort took an olive fruit extract supplying 50 mg of maslinic acid a day. Pain scores and quality-of-life ratings improved more than with placebo, and body weight and BMI fell within the maslinic acid group. The trial was small, with only eight people on placebo.
Joint comfort and mobility scores in a community study
In an open-label study, 29 older residents of a Japanese island ate a daily jelly providing 30 mg of maslinic acid for 16 weeks. The bodily-pain and physical parts of a quality-of-life questionnaire improved, and a knee questionnaire score fell partway through. There was no placebo group, so everyday factors could also contribute to the change.
Muscle mass and grip strength when combined with exercise
In two 12-week placebo-controlled trials, older adults and healthy adults took 60 mg of maslinic acid a day, with one trial also testing 30 mg, while doing resistance or other exercise. Skeletal or trunk muscle mass and grip strength were higher with maslinic acid than placebo, and a knee-pain score improved in the older group. Both trials combined it with training.
Knee function and walking comfort with vibration training
In a 20-week placebo-controlled trial, 26 older women with knee osteoarthritis did whole-body vibration training and took 16.7 mg of maslinic acid a day or placebo. Among those with more advanced knee changes, the maslinic acid group improved on knee muscle torque and on walking-pain and range-of-motion scores. The benefit was seen only in that subgroup.
Muscle soreness and fatigue after hard training in athletes
In a crossover trial, 12 young male water polo athletes took an olive fruit extract giving 60 mg of maslinic acid a day during a week of daily training. Self-rated fatigue and muscle soreness over the training period were lower than with placebo, alongside lower blood markers of inflammation and oxidative stress. The study was funded by an ingredient maker.
Next-day muscle soreness and fatigue after a marathon
In a placebo-controlled trial, 27 amateur marathon runners took maslinic acid or placebo. Blood damage markers changed over time but did not differ between groups, and soreness and fatigue were similar right after the race. One day later, soreness at several sites and overall fatigue were lower in the maslinic acid group, pointing to a recovery effect rather than an immediate one.
Mechanism of action
Calms inflammatory signaling in laboratory models
In immune cells and mouse studies, maslinic acid lowered production of TNF-alpha and other inflammatory messengers and blocked activation of the NF-kB pathway and the phosphorylation of its regulator IkB-alpha. In a mouse arthritis model it reduced paw swelling, arthritis scores and joint tissue damage. These are laboratory and animal findings.
Protects cartilage cells in the lab
In cultured cartilage cells exposed to the inflammatory signal IL-1 beta, maslinic acid lowered nitric oxide, prostaglandin E2 and the cartilage-degrading enzymes MMP-13 and ADAMTS5 by acting on the PI3K/AKT/NF-kB pathway, and it slowed joint changes in a surgical mouse model. This was shown only in cells and mice, not in people.
Supports muscle-maintenance signaling in animals
In mice, maslinic acid reduced loss of muscle mass and strength after nerve injury, raising the growth factor IGF-1 and lowering the muscle-breakdown genes atrogin-1 and MuRF1. This fits the rationale for pairing it with training, but it has not been confirmed as a mechanism in people.
Taken up in a dose-related way when swallowed
In a small human test, blood levels of maslinic acid rose step by step as the dose increased across 30, 60 and 120 mg, showing the compound is absorbed after it is eaten. The test involved only five people, so it gives a rough picture of its uptake.
Clinical trials
Randomized, double-blind, placebo-controlled trial of an olive fruit extract supplying 50 mg maslinic acid a day for 12 weeks; pain and physical function were the primary outcomes, with body composition and inflammatory markers secondary. The paper notes it was a preliminary study not registered in a public database. (Fukumitsu et al. 2016, J Clin Biochem Nutr)
20 middle-aged and older adults (average age 58) with mild knee joint pain (12 on maslinic acid, 8 on placebo).
Both groups improved on a pain visual analogue scale and quality-of-life measures, with better scores in the maslinic acid group. Body weight and BMI fell significantly in the maslinic acid group only. The trial was small, the placebo group had just eight people, and it was not registered.
Open-label community study with no placebo group of a jelly containing 30 mg maslinic acid daily for 16 weeks, with quality of life and a knee questionnaire assessed at five time points. Funded by a flour-milling company through a contracted institute. (Fukumitsu et al. 2017, J Clin Biochem Nutr)
29 elderly residents (average age about 71) of Nakajima Island, Ehime, Japan.
The bodily-pain and physical-component parts of a quality-of-life questionnaire improved, and the Japanese Knee Osteoarthritis Measure fell at week 8, with a trend toward lower pain scores at weeks 4 and 16. Mental quality of life did not change. Open-label with no control group, so results are hard to attribute to the supplement alone.
Parallel, double-blind, randomized, placebo-controlled trial of 60 mg maslinic acid a day versus placebo, both combined with 12 weeks of moderate resistance training; body composition, strength, mobility and knee pain were assessed (registration UMIN000017207). (Nagai et al. 2019, J Clin Biochem Nutr)
36 community-dwelling older adults (17 maslinic acid, 19 placebo).
Skeletal and segmental muscle mass, including the trunk, and the right-leg knee-pain score improved in the maslinic acid group, while the placebo group was unchanged or worse. Grip strength on the better side rose only in the maslinic acid group. Both groups trained, so the exercise is part of any effect.
Double-blind, placebo-controlled, randomized trial of 16.7 mg maslinic acid a day or placebo, both with whole-body vibration training for 20 weeks, in women with knee osteoarthritis of varying severity graded by X-ray. (Yoon et al. 2018, PLoS One)
26 women aged 65 to 85 with knee osteoarthritis.
Among women with more advanced knee osteoarthritis, the maslinic acid group improved on knee extension peak torque and on the pain-on-walking and range-of-motion parts of an orthopaedic score, while the placebo group had few positive results. The benefits were limited to the severe subgroup, and the overall trial was small.
A dose-finding test plus a randomized, double-blind, placebo-controlled trial: five men took 30, 60 or 120 mg to measure blood levels, then 69 adults took placebo, 30 or 60 mg a day with physical exercise for 12 weeks. Involved an olive-ingredient company. (Yamauchi et al. 2023, J Clin Biochem Nutr)
5 healthy men for absorption and 69 healthy Japanese adults for the 12-week trial.
Blood maslinic acid rose step by step with the 30, 60 and 120 mg doses. After 12 weeks, trunk muscle mass and a vitality score were higher in the 60 mg group than placebo, and grip strength was higher in both the 30 and 60 mg groups. Participants also exercised, so training contributed.
Randomized, double-blind, placebo-controlled crossover trial of an olive fruit extract giving 60 mg maslinic acid a day during seven days of daily training; perceptual fatigue, muscle soreness and inflammatory and oxidative-stress proteins were measured. Funded by an ingredient maker whose employees were co-authors. (Shirai et al. 2023, J Int Soc Sports Nutr)
12 young healthy male water polo athletes.
Perceived fatigue and muscle soreness over the training period were significantly lower with maslinic acid than placebo, along with lower blood markers of inflammation and oxidative stress. The trial was small, crossover in design, and industry funded.
Randomized, double-blind, placebo-controlled trial of maslinic acid in amateur marathon runners; subjective soreness and fatigue plus blood damage markers were measured before the race, just after, and one day later. (Tokinoya et al. 2025, J Nutr Sci Vitaminol)
27 healthy amateur runners (19 men, 8 women); 22 to 26 analyzed depending on the measure.
Blood damage markers changed over time but did not differ between groups at any point, and soreness and fatigue were similar right after the race. One day later, muscle soreness at several sites and overall fatigue were significantly lower in the maslinic acid group. The authors frame it as helping next-day recovery, not the immediate response.