Direct Answer: A 2026 systematic review and meta-analysis in the British Journal of Sports Medicine found that PRP injections may shorten return-to-play time after an acute hamstring injury by roughly a week compared to control treatment, especially when the injection is image-guided — but reinjury rates and adverse events were no different between groups, and the certainty of this evidence is still only low to moderate.
What the New Study Found
According to PubMed, a systematic review and meta-analysis by Nakagawa and colleagues, published in the British Journal of Sports Medicine, pooled six randomized controlled trials (277 patients total) evaluating platelet-rich plasma injections specifically for acute hamstring injuries (DOI). The review was deliberately strict about design: only randomized trials comparing PRP to a control treatment were included, and both non-randomized studies and studies of chronic tendinopathy were excluded.
- Return-to-play time was, on average, 8.6 days shorter in the PRP group than in controls (21.4 vs. 30.0 days; p = 0.045) — though heterogeneity between the six trials was high, meaning the studies didn't agree with each other very closely.
- Reinjury rates were statistically identical between groups (15% PRP vs. 16% control).
- Adverse event rates were low and similar in both groups (1% vs. 0%).
- The authors rated the overall certainty of evidence as low to moderate, largely due to risk of bias in the underlying trials and the imprecision that comes with a relatively small pooled sample.
- Notably, the authors specifically flagged that the return-to-play benefit appeared strongest when the PRP injection was image-guided (i.e., performed under ultrasound), rather than delivered as a blind, landmark-based injection.
How This Fits With the Broader Research on PRP and Muscle Injury
It's worth being upfront that this new review doesn't stand alone, and the broader literature on PRP for acute hamstring and muscle injuries has actually been fairly mixed over the past decade or so. At the level of individual trials, the picture is genuinely split:
- Bezuglov and colleagues followed 40 professional soccer players with MRI-confirmed hamstring injuries and found PRP roughly halved return-to-sport time compared to conservative treatment alone (11.4 vs. 21.3 days), with no reinjuries in either group at six months (DOI).
- Hamid and colleagues, in the American Journal of Sports Medicine, randomized 28 athletes with grade 2 hamstring injuries to a single PRP injection plus rehab versus rehab alone, and also found a clear benefit — 26.7 days with PRP versus 42.5 days with rehab alone (DOI).
- Hamilton and colleagues ran a larger, three-arm trial in 90 professional athletes with MRI-confirmed hamstring injuries — PRP, a platelet-poor plasma placebo injection, or no injection at all — and found no benefit of PRP over no injection whatsoever; PRP actually returned athletes to play more slowly than the placebo injection arm. According to PubMed, the authors concluded that intensive, physiotherapy-led rehabilitation remains the primary driver of recovery, not the injection itself (DOI).
The pooled reviews echo that same split:
- According to PubMed, an earlier meta-analysis by Seow et al. in the American Journal of Sports Medicine (10 studies, 356 injuries) found a similar-sized reduction in return-to-play time with PRP, but the difference did not reach statistical significance in their pooled analysis (DOI).
- Grassi et al., in Sports Medicine, found that PRP shortened return-to-play across acute muscle injuries generally, but when they isolated the hamstring-only trials, the benefit disappeared (DOI).
- Pas et al., in an earlier British Journal of Sports Medicine review, went further and found no measurable effect of PRP on acute hamstring injury outcomes at all when compared to control (DOI).
- Sheth et al., in Arthroscopy, found an earlier return to sport with PRP across grade I–II muscle strains overall, but — consistent with Grassi's finding — no significant difference when hamstring strains were analyzed on their own (DOI).
So the honest picture is this: individual trials and prior reviews alike have gone both ways, and PRP's benefit, when it appeared at all, tended to wash out once studies isolated hamstring injuries from the broader category of acute muscle strains, or compared PRP against a true placebo injection rather than no injection at all. The new 2026 Nakagawa review is one of the more favorable results specifically for hamstring injury, and its authors' point about image guidance may be part of the explanation for why it found a clearer signal than some of the older, more heterogeneous evidence. It's also worth noting that dedicated, hamstring-specific PRP trials remain fairly uncommon in the literature — much of what's newest in this space is coming through updated meta-analyses re-examining the existing trial base, like the 2026 review featured here, rather than a wave of brand-new individual studies.
Dr. Tortland's Perspective
This is a good example of why I think it's worth reading past the headline of any single study. Taken alone, this new review is genuinely encouraging for image-guided PRP in acute hamstring injuries — but taken in the context of the last decade of research, including trials that found no benefit or even a signal favoring placebo, it's more accurate to say the evidence is cautiously trending in PRP's favor for this specific injury, not settled. The consistent thread across nearly all of these studies, positive and negative alike, is that reinjury rates don't appear to change either way, and the safety profile remains favorable.
The image-guidance point is one I'd underline for any patient considering this: if you're going to pursue PRP for a hamstring strain, an ultrasound-guided injection — placing the PRP precisely at the site of the muscle tear rather than by anatomical landmarks alone — is the version of this treatment that the current evidence actually supports.
Bottom Line
For an acute hamstring injury, the newest and largest meta-analysis to date suggests PRP may shave about a week off return-to-play time, particularly when image-guided, without any apparent increase in reinjury risk. That said, this builds on a research history where individual trials and prior reviews have gone both ways — including one well-designed placebo-controlled trial that found no benefit at all — so I'd characterize the evidence as promising and improving, not definitive. Further high-quality trials, ideally with more consistent PRP preparation protocols, are still needed.
Primary source: Nakagawa H, Krochmal P, Thomas I, Rabinowitz JB, Kruse RC, Bowers R, Sussman WI. Effects of percutaneous platelet-rich plasma injection on return-to-play after acute hamstring muscle injury: a systematic review and meta-analysis. British Journal of Sports Medicine. 2026;60(5):370-378. https://doi.org/10.1136/bjsports-2025-110683
According to PubMed, all findings referenced above are drawn from indexed, peer-reviewed literature; DOI links to each source are included above for further reading.
