We use PRP (platelet-rich plasma) injections for arthritis and tendonitis. Because PRP comes from your own blood, what you do before and after the injection can make a real difference to how well it works. So what is the PRP injection recovery time, and what should you do before and after to get the best result?

This guide covers preparation and recovery. For evidence supporting PRP, see our platelet-rich plasma injection guide; for costs and contraindications, see the PRP therapy FAQ.

What is platelet-rich plasma?

PRP is a blood sample with a higher platelet concentration. We draw blood from your arm and centrifuge it; the heavier red and white blood cells settle, leaving platelet-rich plasma on top. Those platelets carry growth factors and anti-inflammatory substances that reduce pain and improve function in joints and tendons. The procedure is performed in a clinic in about 45 minutes, with ultrasound guidance for the injection.

PRP injections

What is PRP effective for?

We have evidence for select conditions, not all:

  • Knee arthritis — 23 trials show PRP beats placebo, cortisone, or hyaluronic acid.
  • Hip arthritis — more effective than cortisone; a single injection beats multiple.
  • Achilles partial tears — limited evidence, but we use PRP for partial or interstitial tears.

PRP shows no benefit for thumb, finger, shoulder, or ankle arthritis, or for ankle, foot, and patellar tendonitis.

Risks of PRP injections

Risks are low, as we use your own blood. You may have soreness for a few days (tendon injections hurt more than joints). Infection is possible but rare. Injecting a tendon carries a small risk of rupture — but unlike cortisone, PRP doesn’t weaken tendon structure.

How to prepare for PRP

  • Hydrate well — about 1.5 litres a few hours before.
  • Avoid NSAIDs or aspirin for at least ten days before (check with your doctor if you take aspirin for your heart).
  • Cut caffeine for 24–48 hours before.
  • Tell your doctor about all medications and supplements.

What to do after a PRP injection

  • Rest the injected area — the length depends on the site.
  • Manage pain with ice (15 minutes every 4 hours) and paracetamol, Co-codamol, or Co-dydramol for the first 24–48 hours.
  • Avoid NSAIDs (ibuprofen, aspirin) for at least two weeks.

How long should you rest after PRP?

For a lower-body joint: rest 2 days, minimise walking. Swimming and upper-body weights from day 3, light walking and yoga for a week, lighter lower-body weights for two weeks, running and heavier weights for three weeks.

For a tendon: a, longer. Some tendons (e.g. Achilles) need a CAM boot for 7–10 days. Rest for 3 days, swimming without kicking from day 3, walking from day 10, cross-training and physio from two weeks, and a return to running guided by your physiotherapist.

Day-by-day recovery examples

Tennis elbow

  • Day 0–2: rest, ice, simple painkillers.
  • Day 3–7: lower-body activity — gym, cycling, running.
  • Day 8–14: restart elbow exercises; physio review at day 10.
  • Day 14–28: progress tendon loading; lighter upper-body weights.
  • Day 28+: heavier upper-body weights as guided.

Achilles partial tear

  • Day 0–10: rest in a short boot; upper-body weights from day 2; swimming (no kick) from day 5.
  • Day 11–24: seated calf raises 3x weekly.
  • Day 24–42: standing single-leg calf raises; add weighted isometric holds as advised; keep cycling and walking.
  • Day 42+: graded running programme.

Plantar fasciitis

  • Day 0–7: rest in a short boot; upper-body weights from day 2; swimming from day 3.
  • Day 7–14: supportive shoe for gentle walking; foot-intrinsic exercises.
  • Day 14–21: cycling, more walking, seated calf raises 3x/week.
  • Day 21–28: add standing weighted calf raises; faster walking.
  • Day 28–42: progressive walk/run programme.

Knee arthritis

  • Day 0–2: rest the knee.
  • Day 3–7: upper-body weights and swimming.
  • Day 7–14: walking, cycling, cross-training; lighter lower-body weights.
  • Day 14-21: heavier lower leg weights 
  • Day 21+: brisk walking and running.

Hamstring tendonitis

  • Day 0–7: rest the lower body; upper-body weights from day 2.
  • pos=”106:1-106:60;5790-5849″>Day 7–14:</strong> low-level cycling, cross-training, walking.
  • Day 14–21: strength training.
  • Day 21+: walk/run programme.

Frequently asked questions about PRP recovery.

How soon can I walk after a PRP injection?

For upper-body injections, the next day. For lower-body joints, rest from walking for a week. For lower-limb tendons, walk from about day 10.

Can I drive after a PRP injection?

Avoid driving immediately afterwards; you should be fine the next day.

Why no alcohol after PRP?

Alcohol reduces platelet activation, so avoid it for two days before and up to three days after.

Do ibuprofen or caffeine affect PRP?

Yes — both reduce platelet activation. Avoid NSAIDs and aspirin for 10 days before and 2 weeks after, and cut caffeine for 2 days on either side.

Is a higher platelet count better?

The evidence is contested. One review found systems at concentrations above 4x performed better, and a 5-billion-dose regimen beat 2.5 billion — but a widely quoted 10-billion “optimal dose” claim is based on a flawed study, and other work found higher doses to be less effective. We aim for around 5 billion, achievable in one or several injections.

How long does PRP take to work?

Expect worsening soreness for a few weeks first — that’s the healing response. Joints improve from about four weeks; tendons typically take 6–8 weeks.

Final word from Sport Doctor London about PRP injection recovery time

Simple steps before and after a PRP injection genuinely improve the result. Recovery is usually faster for joint arthritis than for tendonitis. Follow the prep and aftercare, and return to activity gradually under guidance.

To book a one-stop PRP injection in London, contact the team here or call +44 (0) 203 488 0350.

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