Tendon injuries are notoriously slow to heal. Whether it’s Achilles tendinopathy, patellar tendon pain, or a chronic shoulder tendon issue, many people are told to “rest and wait” — only to find the pain lingering for months.

A common question I hear as a physical therapist is:

“Is there anything nutritionally I can do to help my tendon heal?”

The evidence-based answer is yes — when nutrition is paired with the right loading strategy.

Two of the most researched nutrients for tendon repair are collagen and vitamin C. When used correctly, they can support collagen synthesis, tendon remodeling, and long-term tissue resilience.

Why Tendon Healing Is Different From Muscle Healing

Tendons are made primarily of Type I collagen, a dense connective tissue that transfers force from muscle to bone. Compared to muscle, tendons:

• Have limited blood supply
• Adapt slowly (over months, not weeks)
• Require progressive mechanical loading to remodel properly

Because of this, tendon healing depends on:

1. Intelligent loading (rehab and strength training)
2. Availability of the specific nutrients required for collagen synthesis

This is where collagen and vitamin C become relevant.

Why Regular Protein Isn’t Always Enough for Tendon Repair

Most protein supplements are designed for muscle growth. Whey and plant proteins are excellent for muscle, but tendons have different needs.

Collagen is uniquely rich in:

• Glycine
• Proline
• Hydroxyproline

These amino acids are essential for collagen formation but are relatively low in standard protein powders. Even people who eat enough protein may still be under-fueling tendon repair.

Collagen Supplementation for Tendon Healing

Collagen peptides (or gelatin) provide the exact amino acids tendons need to rebuild and adapt.

Research shows that collagen supplementation, when combined with progressive loading:

• Improves tendon structure (cross-sectional area)
• Enhances tendon stiffness and mechanical properties
• Improves pain and function in tendinopathy

Importantly, collagen does not primarily increase muscle mass — its effects are connective-tissue specific, making it ideal for tendon rehab.

Vitamin C and Collagen Synthesis: Why It Matters

Vitamin C is biologically required for collagen formation.

It acts as a co-factor for enzymes responsible for:

• Stabilizing collagen fibers
• Proper cross-linking of collagen
• Improving tensile strength of healing tendon tissue

Without adequate vitamin C, collagen is formed poorly — even if enough collagen amino acids are present.

This does not mean mega-dosing vitamin C heals tendons faster. It means collagen repair cannot occur optimally without sufficient vitamin C.

Timing Matters: When to Take Collagen and Vitamin C

Studies suggest collagen may be most effective when taken before tendon loading.

Why?

• Exercise temporarily increases blood flow to tendons
• Having collagen amino acids circulating during loading may enhance collagen synthesis signaling

This aligns with how tendons biologically adapt to stress.

Evidence-Based Collagen + Vitamin C Protocol for Tendon Healing

30–60 minutes before rehab or tendon loading:

• Collagen peptides or gelatin: 10–15 g
• Vitamin C: 50–200 mg
• Water: 8–12 oz

Frequency:
3–5 times per week, aligned with rehab or training days

Duration:

• Minimum: 8–12 weeks
• Optimal tendon remodeling: 12–24 weeks

This protocol works best when paired with:

• Isometrics
• Slow eccentrics
• Progressive loading strategies

Nutrition supports tendon healing — it does not replace rehab.

Collagen vs Amino Acids: Which Is Better?

Some people ask whether they can just take amino acids instead of collagen.

Both can work, but collagen peptides may offer advantages:

• Naturally high in tendon-specific amino acids
• Provide bioactive peptides that may stimulate fibroblasts
• Simple and practical to use

Amino acid blends can be effective alternatives (especially for dietary or kosher needs), but they must be carefully formulated and still paired with vitamin C.

Who This Approach Is Best For

• Chronic tendinopathy (Achilles, patellar, elbow, shoulder)
• Post-injury tendon remodeling
• Athletes increasing training volume
• Older adults with connective tissue degeneration

When This Approach Is NOT Appropriate

• Acute inflammatory flare-ups without loading tolerance
• Immediately post-surgery before loading clearance
• Individuals with kidney stone risk using high-dose vitamin C

The Bottom Line

Tendon healing is slow by design.

The most effective approach combines:

• Progressive mechanical loading
• Adequate recovery and sleep
• Nutrition that supports collagen synthesis

Collagen and vitamin C don’t “fix” tendons — they help create the biological environment for tendons to adapt when rehab is done correctly.

If you’re dealing with persistent tendon pain, the answer is rarely rest alone.