By the Thrive Protocol editorial team. Medically reviewed by Dr. Patrick Denard, orthopaedic surgeon, on October 19, 2026

Short answer: Your quad is the target. A sports nutrition review suggests 2 to 2.5 g of protein per kg a day while a limb is immobilized, or 150 to 188 g for a 75 kg (165 lb) athlete (2). After protein, leucine and flaxseed oil show early promise, low vitamin D is worth correcting (4), and creatine is not proven in surgical studies but can be an adjunct later if strength is slow to come back (12).

This page covers supplements: what to buy, how much, and when. For meals, a week-by-week eating plan and a grocery list, see What to Eat After ACL Surgery.

Disclosure: this is Thrive Protocol's own site, and we sell some of the products named below. We grade each option on the research, including ingredients we use.

Why ACL reconstruction changes the supplement question

After ACL reconstruction, two things need rebuilding: the graft, which slowly matures into ligament-like tissue, and the quadriceps, which shuts down and shrinks while you are on crutches. Muscle loss starts fast. In young men with a leg in a cast, quadriceps size fell 3.5% and strength fell 9% in 5 days; after 14 days, strength was down 22.9% (1). If you play a sport, the goal is not just recovery but getting back on the field, and quad strength is a big part of that.

That shapes the plan. Feed the quad hard early, support collagen for the graft, and save performance supplements for the strength phase.

What to take after ACL surgery: the short list

Supplement Job after ACL reconstruction How much When Evidence in ACL patients
Protein (whey) Limit quad loss, fuel rehab 2 to 2.5 g/kg a day during immobilization (review) Prehab through return to sport Moderate (linked to better muscle and function)
Leucine Switch on muscle building 3 g a day Prehab through return to sport Limited (1 small trial)
Flaxseed oil (omega-3 ALA) Normal inflammatory response 9 g oil with 4.2 g ALA daily for 2 years From surgery onward Limited (1 trial, 142 patients)
Vitamin D Correct a low level RDA 600 IU; more only if low Test before surgery Limited (observational)
Collagen blend with vitamin C Graft and connective tissue Daily blend for 90 days in one trial First 3 months Limited (1 trial)
Creatine Adjunct for regaining strength 5 g a day Later in recovery, especially if strength is slow to return Not proven in surgical studies
Vitamin E pills Antioxidant With vitamin C, from 2 weeks before to 3 months after surgery n/a Not supported (keep vitamin C from food)
Glucosamine Joint support n/a n/a Not supported

1. Protein: the one with real support

What the reviews found: a 2026 systematic review of 15 ACL nutrition studies found that higher protein intake alongside physical therapy was linked to better muscle retention and function. It also flagged serious risk of bias in most of the studies (4). An earlier review of 10 ACL trials concluded that protein-based supplements may help limit muscle loss, but that no specific protocol could be recommended yet (5).

How much: a review on injured athletes suggests 2 to 2.5 g/kg a day during immobilization, and at the very least not cutting protein when you cut calories (2). For a 75 kg athlete: 75 x 2.0 = 150 g and 75 x 2.5 = 188 g a day. That is five servings of about 30 to 38 g. Spread them out; even distribution produced 25% more muscle protein synthesis over 24 hours than a dinner-heavy pattern (3).

Why a supplement helps: on crutches, few people eat five protein-rich meals. A shake closes the gap.

2. Leucine: small but specific

In a double-blind trial of 45 athletes in the return-to-sport phase, the leucine group gained more thigh girth 10 cm above the kneecap than the placebo group. Strength and the other measures did not differ significantly (6). Leucine is the amino acid that triggers muscle building, and whey is rich in it. A practical target is 3 g of leucine a day.

3. Flaxseed oil: one notable trial

In a randomized trial of 142 patients aged 15 to 45 analyzed after early ACL reconstruction, the group taking 9 g of flaxseed oil a day (4.2 g of the plant omega-3 ALA) for 2 years had better knee scores (IKDC and KOOS) and a higher rate of return to their pre-injury sport level than a corn oil placebo group (7). Limits: one single-center trial, and patients who dropped out were not analyzed. The 2026 review called flaxseed oil promising, not proven (4).

4. Vitamin D: test it early

In 21 young athletes having ACL reconstruction, those with vitamin D below 30 ng/mL lost more quadriceps fiber size at 1 week and 4 months than those at 30 ng/mL or above (8). It is a small observational study, so it shows a link, not proof that supplements help. The RDA is 600 IU a day for ages 1 to 70 (9). Ask for a blood test before surgery and let your doctor set the dose if you are low.

5. Collagen for the graft: one interesting trial

In a randomized trial of 72 ACL patients, a daily supplement of hydrolyzed collagen peptides, plasma proteins, a hyaluronic acid and chondroitin complex, and vitamin C was added to physical therapy for 90 days. At 90 days, 61.8% of the supplement group showed more advanced graft maturation on MRI, versus 38.2% of controls, and they used fewer therapy sessions (10). Because it was a blend, collagen alone cannot take the credit. Separately, 15 g of vitamin C-enriched gelatin before exercise doubled a collagen synthesis marker in healthy men (11).

6. Creatine: an adjunct, not proven in surgery

Creatine has not been proven in surgical studies. In 60 ACL patients, it had no effect on strength or power in the first 12 weeks of rehab (12). But in healthy volunteers whose leg was in a cast for 2 weeks, creatine during a 10-week retraining program helped quadriceps size and power recover faster (13), so it can be a reasonable adjunct to rehab. The usual amount is 5 g a day. If you are later in your recovery and struggling with regaining strength, it is also worthwhile considering. If you are under 18, check with your surgeon or a sports dietitian before starting.

Skip these

  • Vitamin E pills. In 20 men, vitamin E and C supplements from 2 weeks before to 3 months after surgery did not improve strength recovery (14), and vitamin E is on the list of supplements that can affect bleeding around surgery. Vitamin C is different: your body needs it to make collagen, and in the same trial, men with better vitamin C intake from their diet regained more strength. Keep getting vitamin C from food or a modest daily amount.
  • Glucosamine. A 2023 review of 6 ACL trials found no significant strength or muscle benefit from glucosamine (15).

ACL supplement timeline

Phase Your knee Supplement focus
Prehab (weeks before) Swelling down, range of motion back Vitamin D test. Daily protein shake. Supplement list to your surgeon.
Days 1 to 14 Crutches, brace, quad activation Protein at every feeding, even with low appetite. Collagen and vitamin C if your surgeon agrees.
Weeks 2 to 6 Walking, regaining motion Keep protein near your target. Do not diet down.
Weeks 6 to 12 Strength work ramps up Protein within a couple of hours after therapy.
Month 3 to return to sport Running, jumping, sport drills Keep leucine going. Creatine, 5 g a day, is worth considering if strength is slow to return.

Every surgeon's protocol differs, especially with meniscus repair, so line these phases up with your own rehab plan.

Individual supplements vs an all-in-one kit

Option What it covers for ACL recovery What it leaves out Testing Price
Separate products (whey, leucine, vitamin D, flaxseed oil, later creatine) Each item at a dose you choose Depends on what you buy Varies; check for third-party sport testing if you compete Varies by brand
Surgical Protocol Kit OptiFuel packet: 25 g protein (whey plus hydrolyzed collagen), 3 g leucine, glutamine, 500 mg vitamin C, 800 IU vitamin D, plus magnesium, calcium, B vitamins, fish oil and turmeric extract. OptiCharge for the night before Creatine, flaxseed oil, zinc, iron Informed Sport tested 4-week $299.99, 3-month $499.99, 6-month $669.99
Recovery Protocol Kit Same OptiFuel, no OptiCharge Creatine, flaxseed oil, zinc, iron Informed Sport tested 4-week $289, 3-month $499, 6-month $669
Recovery and Strength Mix Per scoop: creatine 5 g, leucine 3 g, glutamine 2.5 g, arginine 2 g, isoleucine 1.75 g, valine 1.75 g Whole protein, vitamins Informed Sport certified $49.99

Creatine and arginine are only in the Recovery and Strength Mix. OptiFuel's omega-3 comes from fish oil, which is not the flaxseed oil used in the ACL trial above.

Supplement safety before ACL surgery

  • Fish oil, curcumin or turmeric, ginkgo, garlic, vitamin E and similar supplements can affect bleeding (17). Your surgeon sets the stop dates before surgery. In a large heart surgery trial, perioperative fish oil did not increase major bleeding (16), but your own team's list wins.
  • OptiFuel contains fish oil and turmeric. There is no need to stop OptiFuel before surgery, but your own surgeon's instructions always come first.
  • Some high-bioavailability curcumin products have been linked to liver injury (18).
  • If you are prescribed a blood thinner after surgery, ask before restarting any supplement.

Where to get it

  • Reconstruction scheduled: the Surgical Protocol Kit. Start 1 week before surgery, alongside your prehab. OptiCharge is for the night before. 4-week $299.99, 3-month $499.99, 6-month $669.99.
  • Already on crutches: the Recovery Protocol Kit, the same daily OptiFuel packet. 4-week $289, 3-month $499, 6-month $669.
  • Strength and return-to-sport phase: the Recovery and Strength Mix, $49.99. Ideally, everyone on a kit also takes the Recovery and Strength Mix daily.

Thrive Protocol kits are HSA/FSA eligible, so you can use pre-tax health dollars. Check with your surgeon before starting.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Get the free Surgery Recovery Guide for the full plan on one page.

Frequently asked questions

What are the best supplements after ACL surgery?

Protein has the best support for keeping quad muscle. Leucine and flaxseed oil show early promise, and correcting low vitamin D makes sense. Creatine is not proven in surgical studies but can be an adjunct later in recovery.

Should I take creatine after ACL surgery?

Creatine is not proven in surgical studies: a 60-patient ACL trial found no strength benefit in the first 12 weeks. It can be an adjunct later. The usual amount is 5 g a day, and if you are later in your recovery and struggling with regaining strength, it is worth considering. Check with your surgeon first, especially if you are under 18.

Does collagen help after ACL reconstruction?

One trial of a collagen-containing blend saw more advanced graft maturation at 90 days. It was a mix of ingredients, so the effect of collagen alone is unknown.

How much protein do I need after ACL surgery?

A review on injured athletes suggests 2 to 2.5 g/kg a day during immobilization. For a 75 kg athlete, that is about 150 to 188 g, spread over five servings.

What should drug-tested athletes look for in recovery supplements?

Choose products with third-party sport testing. Thrive's kits are Informed Sport tested and the Recovery and Strength Mix is Informed Sport certified. Check your league's rules too.

Related reading

References

  1. Wall BT, et al. Substantial skeletal muscle loss occurs during only 5 days of disuse. Acta Physiol (Oxf). 2014. PubMed 24168489
  2. Tipton KD. Nutritional support for exercise-induced injuries. Sports Med. 2015. PubMed 26553492
  3. Mamerow MM, et al. Dietary protein distribution positively influences 24-h muscle protein synthesis in healthy adults. J Nutr. 2014. PubMed 24477298
  4. Raghoebar S, et al. Nutrition and rehabilitation after anterior cruciate ligament reconstruction: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2026. PubMed 42171084
  5. Greif DN, et al. Supplement use in patients undergoing anterior cruciate ligament reconstruction: a systematic review. Arthroscopy. 2020. PubMed 32438028
  6. Laboute E, et al. Rehabilitation and leucine supplementation as possible contributors to an athlete's muscle strength in the reathletization phase following anterior cruciate ligament surgery. Ann Phys Rehabil Med. 2013. PubMed 23260415
  7. Tang H, et al. Effect of dietary flaxseed oil on the prognosis of acute anterior cruciate ligament rupture: a randomized placebo-controlled trial. Am J Transl Res. 2022. PubMed 36398219
  8. Wen Y, et al. Vitamin D status associates with skeletal muscle loss after anterior cruciate ligament reconstruction. JCI Insight. 2023. PubMed 37856482
  9. Ross AC, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine. J Clin Endocrinol Metab. 2011. PubMed 21118827
  10. López-Vidriero E, et al. Efficacy and tolerability of Progen, a nutritional supplement based on innovative plasma proteins, in ACL reconstruction: a multicenter randomized controlled trial. Orthop J Sports Med. 2019. PubMed 30834280
  11. Shaw G, et al. Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. Am J Clin Nutr. 2017. PubMed 27852613
  12. Tyler TF, et al. The effect of creatine supplementation on strength recovery after ACL reconstruction: a randomized, placebo-controlled, double-blind trial. Am J Sports Med. 2004. PubMed 14977662
  13. Hespel P, et al. Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol. 2001. PubMed 11600695
  14. Barker T, et al. Vitamin E and C supplementation does not ameliorate muscle dysfunction after anterior cruciate ligament surgery. Free Radic Biol Med. 2009. PubMed 19751822
  15. Lapaeva AG, et al. Effect of dietary supplements and whey protein on muscle mass and strength of the operated limb after anterior cruciate ligament reconstruction: a systematic review [in Russian]. Vopr Pitan. 2023. PubMed 37346024
  16. Akintoye E, et al. Fish oil and perioperative bleeding. Circ Cardiovasc Qual Outcomes. 2018. PubMed 30571332
  17. Wang CZ, et al. Commonly used dietary supplements on coagulation function during surgery. Medicines (Basel). 2015. PubMed 26949700
  18. National Center for Complementary and Integrative Health. Turmeric: usefulness and safety. nccih.nih.gov/health/turmeric

This guide is for education and does not replace advice from your surgeon, physical therapist or care team. Product details checked against mythriveprotocol.com product pages on 18 October 2026.