Period Hormones and ACL Knee Injuries
What is the ACL? The anterior cruciate ligament (ACL) is “one of the two ligaments that cross in the middle of the knee. It connects your thigh bone to your shinbone and helps keep the knee joint stable.” (Mayo Clinic)
Injuries to the ACL often occur during sports when fast or sudden movements like jumps, pivots or changes in direction occur while in motion. Sometimes a ‘pop’ is felt in the knee during injury. It can cause knee swelling, instability, pain, diminished range of motion and difficulty bearing weight on the injured leg.
Hormones can influence and effect the integrity of our tissues. People who have menstrual cycles and/or were assigned female at birth (AFAB) experience fluctuations of hormones in a cyclical manner. Hormones such as estrogen, progesterone, testosterone and relaxin can influence collagen production, ligaments and therefore the mechanical properties of their joints. Changes and fluctuations in hormones can influence the strength and stability of the ACL during varying times of the menstrual cycle. (Schultz et. al, 2023)
Athletes who are assigned female at birth are considered at an increased risk for ACL injuries due to hormonal variation and its effects on certain tissues. It is suggested that relaxin, a hormone which is present in the second half of the menstrual cycle could be causing collagen degrading effects to certain tissues, making the ACL more vulnerable to injury during this time. A 2024 review looked at the correlation between menstrual relaxin peaks with the rate of ACL injuries and found that cycle days 21-24 were associated with greater risk of ACL injury while those on oral contraception reduced the presence of relaxin which may provide a more protective effect. (Parker et. al)
Acupuncture Compared to Birth Control
Acupuncture can help with a lot of conditions that involve hormonal imbalances like fertility, period problems, perimenopause and hot flashes.
In 2015 a randomized control trial, acupuncture was compared with combined oral contraceptive pills (BCP) to treat moderate to severe painful period cramps. The researchers looked at: the highest level of menstrual pain intensity, the number of days cramps lasted for, the amount of pain medication was used, quality of life as well as overall treatment response and any adverse effects. It was found was that both methods produced significant improvements in reduction of pain, fewer days of pain and decreased need for pain medication as well as an overall improvement of quality of life. While BCP reduced the pain intensity better, those that had acupuncture reported less hormonal side effects.
Acupuncture and Knee Injuries
Acupuncture is known to relieve pain by releasing the body’s natural pain killers. Acupuncture can also speed up the healing process by releasing corticosteriods which will reduce inflammation. (2016, Patil et al. ) Acupuncture is great for joint injuries because it can reach deep inside a join in order to bring more circulation to tissues like tendons, ligaments, cartilage and bones which do not heal as easily as muscle tissue.
A 2020 study by Shi et al. compared electroacupuncture to manual acupuncture on knee osteoarthritis showed that both methods “reduced pro-inflammatory cytokines, and cartilage degradation biomarkers” while also increasing an anti-inflammatory cytokine, significantly. In 8 weeks during the study, participants with mild to moderate knee osteoarthritis showed improvement in pain relief and overall function.
A 2017 meta-analysis of 17 studies (Zhang et al. ) concluded that acupuncture helps with chronic knee pain after 12 weeks of treatment.
What to Expect with Acupuncture
Acupuncture is great therapy to have regularly for competitive athletes. It can help prevent injury as well as address any pain or injury at an earlier stage. Some knee injuries can be resolved if you are able to get treatment sooner than later and this can prevent an acute situation from becoming chronic. Many sports put the knee joint under a lot of stress and for some people, having surgery is unavoidable. Acupuncture can also be helpful in the post-operative and rehab stages to speed recovery. In these cases it is important to expect to have acupuncture at a minimum, on a weekly basis. When it comes to hormonal conditions or factors weekly acupuncture is also recommended. With sports injuries it is always important to be assessed by your orthopedic doctor.
Written by Dr. Emily Siy, DACM on 9/25/26 posted on 10/19/26
Use the code ‘PREPARE’ for $20 off an already discounted acupuncture 3 pack
You might also be interested in reading: Chinese Medicine for PCOS, My Ankle Sprain Recovery, Knee Case Comparison
Sources
Parker, E. A., Duchman, K. R., Meyer, A. M., Wolf, B. R., & Westermann, R. W. (2024). Menstrual cycle hormone relaxin and ACL injuries in female athletes: A systematic review. Iowa Orthopaedic Journal, 44(1), 113–123.
Patil, S., Sen, S., Bral. M., Reddy, S., Bradley, K.K., Cornett, E.M., Fox, C.J., Kaye, A.D. (2016) The Role of Acupuncture in Pain Management. Current Pain and Headache Reports 20:22
Shi, GX, Tu JF, Wang TQ, Yang JW, Wang LQ, Lin LL, Wang Y, Li YT, Liu CZ. (2020) Effect of Electro-Acupuncture (EA) and Manual Acupuncture (MA) on Markers of Inflammation in Knee Osteoarthritis. Journal of Pain Research 13:2171-2179
Shultz, S. J., & Fegley, J. A. (2023). The effect of sex hormones on ligament structure, joint stability and ACL injury risk. In A. C. Hackney (Ed.), Sex hormones, exercise and women: Scientific and clinical aspects (pp. 167–195). Springer.
Sriprasert, I., Suerungruang, S., Athilarp, P., Matanasarawoot, A., & Teekachunhatean, S. (2015). Efficacy of acupuncture versus combined oral contraceptive pill in treatment of moderate-to-severe dysmenorrhea: A randomized controlled trial. Evidence-Based Complementary and Alternative Medicine, 2015, Article 735690
Zhang, Q., Yue, J., Golianu, B. (2017) Updated Systemic Review and Meta-Analysis of Acupuncture for Chronic Knee Pain Acupuncture Medicine Dec; 35 (6): 392-403