NOTE: The brand of ARA used in the study covered in this article – the brand with longest track record and most extensive feedback by users – is X Factor by Molecular Nutrition. For companies looking to carry ARA, the manufacturer of ARA is Cargill and the contact (wholesale inquiries only) is firstname.lastname@example.org
I recently did a video on ARA which discusses this study that found ARA had positive effects on strength and muscle mass, but was not able to give details because it had yet to be published as an abstract or full paper. The study results are now public and I cover them below. Two previous articles on ARA ( Part I), by Monica M cover why ARA is a generally misunderstood fatty acid and not a a negative to health, (part II ) covered the safety of ARA as a supplement. Finally, Part III, cuts through the hype and bro-science to give details on ARA and it’s use as a supplement for increasing strength and muscle mass! My understanding is a full paper is in process that will also examine the specific mechanisms of ARA and its impact on strength, muscle mass, and performance.
This study looked at the effects of 1.5g per day of ARA for 8 weeks on muscle hypertrophy, body composition, strength, and power, compared to a placebo matched control. For those who don’t enjoy reading abstracts and studies, here’s the cliffs notes followed by the full details:
• The group receiving 1.5g of ARA had in increase in lean body mass (LBM) of approx 3%, corresponding to 3.5 lb (1.6 kg) compared to no changes in the placebo group
• Muscle thickness increased in the group receiving ARA (+9.5%) vs. the placebo group (+4.7%).
• There was an improvement in anaerobic power (via Wingate test which measures 30 second maximal output), which increased in the group getting ARA (+10.7%) vs. the placebo group (+3.8%).
• The group receiving ARA increased their bench press and leg press strength to a greater degree than the placebo group.
Full Study Details:
Effects of Arachidonic Acid Supplementation on Skeletal Muscle Mass,
Strength, and Power
Jacob Ormes1, Matthew H. Sharp, Jordan M. et al.
Department of Health Sciences and Human Performance, The University of Tampa, Department of Health and Exercise Science, Auburn University
Arachidonic acid (ARA) is a long-chain omega-6 polyunsaturated fatty
acid that can be integrated into membrane phospholipids and it is the primary
substrate for COX-2-mediated biosynthesis of prostaglandins .
Previous research found that ARA could enhance power and tended to
increase strength and hypertrophy . However, a lack of power likely
prevented these values from reaching significance. Therefore, the purpose
of this study was to investigate the effects of 8 weeks of arachidonic
acid supplementation in individuals participating in a periodized resistance
training program on skeletal muscle hypertrophy, body composition,
strength, and power relative to a placebo matched control.
Materials & Methods
Thirty recreationally-trained males aged 20.4 ± 2.1 years with a respective
average leg press and bench press of 231.5 ± 55.6 kg and 103.9 ± 26.8 kg
and a minimum of 1 year of resistance training experience were recruited
for the study. All subjects participated in an 8-week, 3-day per week,
resistance-training program that was split-focused on multi-joint movements
such as leg press, bench press, and bent-over rows. Ultrasonography
measured muscle thickness of the quadriceps, dual-energy X-ray
absorptiometry (DEXA) determined lean body mass, power, and strength
of the bench press and leg press were determined at weeks 0, and 8 of
There were time, and group-by-time interactions for LBM (p<0.05) in
which LBM increased from pre (Placebo 57.7± 4.8kg; ARA 57.6 ± 5.0kg,)
to post (Placebo 57.8 ± 5.6kg; ARA 59.3 ± 5.0 kg,) only in ARA group, but
not the placebo. Delta change of LBM was significantly greater in the ARA
group (1.62 ± 0.01kg) than the placebo (0.09 ± 0.7) (p<0.05). The Delta
change for muscle thickness was greater in the ARA group (.47 ± .08 cm)
than the placebo (.25 ± .04 cm) (p<0.05). There was a time, and group by
time interaction for wingate power, in which power increased to a greater
extent in ARA (723.01± 104.53 W to 800.66 ± 112.60 W) than the placebo
(738.75 ± 129.76 to 766.51 ± 136.52 W). Delta change for total strength
was greater in the ARA group (109.92 ± 33.25) than the placebo (75.78
These results suggest that ARA supplementation can positively augment
adaptations in strength and skeletal muscle hypertrophy in resistance-
trained men. Athletes and everyday individuals looking to maximize
their body composition, strength, and power could use ARA as an ergogenic