ACL Injury: How Combining Rehabilitation with Supplements Helps You Recover Faster

12 June 2024


  • ACL injuries are common in the UK, affecting about 1 in every 3000 individuals.
  • Incorporating nutritional support with exercise and supplementation can increase collagen production during ACL healing.
  • Collagen supplementation following ACL reconstruction may increase the efficacy of physiotherapy. It can also reduce the time needed to return to pre-injury activities.
  • Adding other nutrients, such as vitamin C, beta-carotene, and zinc, may offer additional benefits.

This article examines aspects of ACL injury recovery and whether collagen supplements for knee ligaments can make the healing process more efficient.

What Are ACL Injuries?

The anterior cruciate ligament (ACL) is a band of tough connective tissue in the middle of the knee connecting the femur (thighbone) to the tibia (shinbone).

The ACL helps keep your knee joint stable and allows you to control the back-and-forth movement of the lower leg.

An ACL injury is a type of knee injury. It occurs when the ACL is partially or completely torn and usually happens when the ligament is placed under excessive and /or sudden excessive load. 

Sports involving sudden stops/starts and changes of direction tend to see higher rates of ACL injuries, e.g. football, rugby, and skiing.

What Happens During An ACL Injury?

ACL tears may occur if your lower leg is twisted, or extends forward more than it should (hyperextension). If there are tears in the ligament, the body tries to heal the injured ACL by increasing collagen production, particularly within the first few weeks after injury.

The ruptured ACL may heal with or without surgery. Nonetheless, rehabilitation is essential in both cases to aid healing and strengthen the tissues to regain stability in the joint.

What Happens During ACL Rehabilitation and Healing?

Rehabilitation and ACL healing go hand in hand.

ACL rehabilitation involves several targeted exercises that aim to: (1)

  • Reduce pain and swelling
  • Help you regain full movement of the knee
  • Restore pre-injury strength and stability
  • Help you walk without a limp

During healing, collagen is deposited into the ACL periphery as the body adapts to progressive loading. Simply put, applying progressive load to the ACL causes the ACL to respond by increasing collagen production to repair and strengthen the ligament.

Evidence shows that supplementing with collagen during this period can enhance tissue regeneration and speed recovery by providing the body with the nutritional building blocks for collagen formation. (2)

Rehabilitation Plus Collagen Supplementation For Faster Recovery

Maintaining a collagen-rich ECM (extracellular matrix) is crucial to a strong ACL. The ECM is a network of proteins and other substances that support and give structure to the ACL.

According to a 2022 study, three amino acids in collagen—proline, hydroxyproline, and hydroxylysine—enhance collagen production when taken with vitamin C. (3)

Hydrolyzed collagen supplementation following ACL reconstruction can increase the efficacy of physiotherapy. Consequently, those who take the supplement will likely return to pre-injury activities earlier and use lower quantities of pain medications. (4)

ACL injuries may also damage other structures, such as the knee cartilage. As a cushion, the knee cartilage reduces friction in the knee joints.

Fortunately, collagen supplements can help reduce cartilage damage associated with an ACL injury.

An animal study shows that 6-week collagen supplementation can reduce cartilage damage by preventing the body from making inflammatory substances. (5)

Choosing A Collagen Supplement: Things to Know

After an ACL injury, the body initiates a repair process that begins with inflammation. During this period, fibroblasts (cells that produce collagen) are recruited to the injury site.

Type III collagen is produced in larger amounts initially because it is associated with the formation of granulation tissue, which is the new connective tissue and tiny blood vessels that form on the surfaces of a wound during the healing process.

All ligaments, including the ACL, are made primarily of Type I collagen.  Type III collagen is like a temporary scaffold. As the healing process progresses, Type I collagen gradually replaces Type III collagen. This remodelling phase is critical for restoring the ligament’s strength and functionality. Type I collagen provides high tensile strength.

When it comes to dosage, experts recommend 10 to 15 g of hydrolyzed collagen per day to help prevent and treat joint, tendon, and ligament injuries. (6)

Liquid collagen supplements containing type I and III collagen can enhance ACL injury recovery. 

Cutizana contains 10,000mg of type I and III collagen – see more.


  1. Royal United Hospitals Bath NHS Foundation Trust. Prehabilitation Programme for an Anterior Cruciate Ligament (ACL) Injury.
  2. Shaw, Gregory et al. “Rehabilitation and nutrition protocols for optimising return to play from traditional ACL reconstruction in elite rugby union players: A case study.” Journal of sports sciences vol. 37,15 (2019): 1794-1803. doi:10.1080/02640414.2019.1594571
  3. Nyland, J et al. “ACL microtrauma: healing through nutrition, modified sports training, and increased recovery time.” Journal of experimental orthopaedics vol. 9,1 121. 14 Dec. 2022, doi:10.1186/s40634-022-00561-0
  4. López Vidriero, E et al. “Efficacy and Tolerability of a Dietary Supplement Containing Collagen, Hyaluronic Acid, Chondroitin Sulfate and Plasma Proteins in the Recovery After Anterior Cruciate Ligament Reconstruction.” Orthopaedic Journal of Sports Medicine vol. 6,6 suppl3 2325967118S00040. 28 Jun. 2018, doi:10.1177/2325967118S00040
  5. Felim J, Chen C-K, Tsou D, Kuo H-P and Kong Z-L (2022) Effect of Different Collagen on Anterior Cruciate Ligament Transection and Medial Meniscectomy-Induced Osteoarthritis Male Rats. Front. Bioeng. Biotechnol. 10:917474. doi: 10.3389/fbioe.2022.917474 
  6. Turnagöl, Hüseyin Hüsrev et al. “Nutritional Considerations for Injury Prevention and Recovery in Combat Sports.” Nutrients vol. 14,1 53. 23 Dec. 2021, doi:10.3390/nu14010053