How long does PRP injection take to work for a hamstring strain?

PRP uses a concentrated part of a person’s blood, prepared and placed at the injured area. The injection does not act like an instant painkiller, and soreness can increase briefly after the procedure. Improvement is usually assessed through pain during walking, strength testing and the ability to load the hamstring without a flare-up.

A strain near the muscle belly may behave differently from an injury close to the tendon or sitting bone. The size and age of the injury, previous setbacks, sleep and the rehabilitation plan all affect timing. PRP is not suitable for every hamstring problem, so the diagnosis should guide the decision.

Follow the injection team’s instructions about rest, medication and the timing of physiotherapy. Avoid sprinting, deep stretching and heavy hamstring loading until cleared. Rehabilitation commonly progresses from comfortable movement to controlled strengthening, then faster running and sport drills. Increase only one demand at a time and note pain during activity and the following day.

Contact the treating clinician for worsening pain, spreading redness, increasing warmth, drainage or fever after the injection. Seek urgent care for new severe weakness, extensive swelling, numbness or inability to walk. A review is also appropriate when progress stalls or running repeatedly causes sharp pain.

Where exactly is my hamstring injury? What activity limits apply after the injection? When should strengthening begin? How will you decide whether the injection and rehabilitation are helping?