Which Medications Should You Stop Before a PRP Injection?
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By Dr. Jeffrey Peng, MD · Published March 6, 2026 · 8 min read
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Platelet-rich plasma (PRP) injections have become a widely studied treatment option for tendon conditions such as tennis elbow, fascial problems such as plantar fasciitis, and joint conditions such as osteoarthritis. PRP is increasingly used as a first-line therapy because it is both safe and effective. However, one often-overlooked factor that can significantly influence your outcomes is the medications you take in the weeks surrounding your procedure.
Certain medications — particularly nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (Tylenol) — can impair platelet function and potentially reduce the effectiveness of your PRP treatment. There are currently no formal guidelines on which medications should be stopped before a PRP injection, but the existing research provides valuable insight into how to optimize your results.
Why Should You Stop NSAIDs Before a PRP Injection?
The NSAID class of drugs should generally be stopped one to two weeks prior to a PRP injection. The reason is straightforward: most NSAIDs work by inhibiting platelet function. PRP relies on the growth factors released by activated platelets to initiate healing. If you take an NSAID before your procedure, the platelets drawn from your blood may be functionally impaired — unable to release the essential growth factors that drive the therapeutic response.
Common NSAIDs include aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), diclofenac, celecoxib (Celebrex), meloxicam (Mobic), and indomethacin. A systematic review by Kao et al. (2022) evaluated the effects of common medications on platelet count and function. The authors concluded that aspirin, acetaminophen, and nonselective NSAIDs should be considered for suspension before a PRP injection due to their potential to diminish the effects of the treatment. Notably, COX-2 selective NSAIDs such as celecoxib did not show a significant decrease in platelet aggregation.
How Does Aspirin Affect PRP Growth Factor Release?
A prospective laboratory study by Jayaram et al. (2019) examined how low-dose aspirin affected growth factor release from platelet-rich plasma. Twelve healthy male volunteers had their blood drawn to establish baseline whole blood counts, PRP concentrations, and levels of three critical growth factors: TGF-beta-1, vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF).
The same twelve volunteers then took 81 mg of aspirin daily — a standard baby aspirin dose — for 14 days. After two weeks, the researchers repeated all blood analyses. They found that platelet and white blood cell counts remained unchanged from baseline. However, despite the same number of platelets being present, those platelets were no longer functional. They could not signal the release of any of the three essential growth factors.
The takeaway is clear: even low-dose aspirin can render your platelets unable to initiate the cascade of growth factor release that PRP depends on. If your platelets cannot release growth factors, you are unlikely to achieve an optimal outcome from your procedure.
Do NSAIDs After a PRP Injection Affect Outcomes?
This is an equally important question. A controlled laboratory study by Sok et al. (2022) used a rodent model of post-traumatic osteoarthritis to investigate how NSAID timing affected the efficacy of biologic injections. Rats underwent surgery to transect their meniscus and induce arthritis, then received human mesenchymal stem cell (MSC) injections. The rats were divided into four groups based on their NSAID exposure:
One group received naproxen only before the injection. A second group received naproxen only after the injection. A third group received naproxen both before and after the injection. The final group received no NSAIDs at all — only the stem cell treatment.
The results were striking. The group that received naproxen after the injection and the group that received naproxen both before and after had significantly worse outcomes, including greater cartilage degeneration, more bone spur formation, and increased pain. The best results were seen in the group that received no NSAIDs at all — their cartilage remained relatively smooth with less degeneration overall.
Interestingly, the group that received naproxen only before the injection had outcomes similar to the no-NSAID group. While they had reduced proteoglycan levels — a molecule important for cartilage integrity — there was still a meaningful protective effect on cartilage degeneration. The researchers concluded that NSAID use before biologic injections only minimally reduced outcomes, but NSAID use after injections substantially reduced the therapeutic efficacy of the treatment.
Why Acute Inflammation Matters After PRP
Understanding why NSAIDs are harmful after a PRP injection requires appreciating the role of acute inflammation in healing. A study published in Science Translational Medicine by Parisien et al. (2022) demonstrated that the initial acute inflammatory response — specifically driven by neutrophil activation — actually protects against the development of chronic pain. In both human subjects and mouse models, early suppression of inflammation with NSAIDs or steroids led to prolonged pain despite providing short-term relief.
This finding reinforces the concept that acute inflammation following a PRP injection is not something to suppress — it is a necessary part of the healing process. The growth factors released by activated platelets trigger an inflammatory cascade that signals the body to begin repairing injured tissue. Blocking that response with NSAIDs can directly interfere with the mechanism that makes PRP effective.
Can You Take Tylenol (Acetaminophen) Before PRP?
Acetaminophen presents a more nuanced situation. A comprehensive review by Driver et al. (2020) examined the effects of NSAIDs and paracetamol (acetaminophen) on platelet function. The prevailing assumption has long been that acetaminophen has limited or no antiplatelet effects compared to aspirin. However, the evidence is mixed — some studies show that acetaminophen does have antiplatelet effects, while others suggest it does not.
The authors suggest that these conflicting results likely stem from differences in study design and the methods used to measure platelet function. In my practice, I still tell patients that it is acceptable to take acetaminophen around the time of their PRP injection. The primary reason is practical: most patients undergoing PRP have pain and rely on NSAIDs for relief. If they cannot take NSAIDs for one to two weeks before and several weeks after the procedure, acetaminophen becomes the only remaining over-the-counter option for pain control. Removing that option entirely can be quite difficult for patients.
That said, for patients who want to be especially cautious and whose pain levels are tolerable, I recommend holding both NSAIDs and acetaminophen before and after the injection. If pain control is necessary, a low dose of acetaminophen taken as needed is a reasonable approach.
How Long Should You Stop Medications Before and After PRP?
This is an area that has not been well studied, and there are no clinical trials that directly address optimal medication cessation timelines. Based on the available evidence and my clinical experience, I recommend the following approach:
Before the injection: Stop all NSAIDs at least one week before your PRP procedure. If possible, two weeks is preferable to allow full recovery of platelet function.
After the injection: Avoid NSAIDs for at least two weeks after your PRP treatment. Ideally, hold them for up to six weeks. The animal study by Sok et al. clearly demonstrated that NSAID use in the weeks following a biologic injection significantly impaired outcomes. The longer you can avoid NSAIDs after treatment, the better your results are likely to be.
If you need pain relief during this period, acetaminophen at a low dose is a reasonable alternative. You should always discuss your specific medication regimen with your treating physician, as individual circumstances may vary.
The Bottom Line
The medications you take around the time of your PRP injection can meaningfully affect your outcomes. NSAIDs inhibit platelet function and suppress the acute inflammatory response that is essential for PRP to work. The research consistently shows that the best outcomes occur when patients avoid NSAIDs both before and after their procedure. Acetaminophen remains a reasonable alternative for pain management, though patients who can tolerate holding all medications may achieve the best possible results.
If you are considering platelet-rich plasma therapy or have questions about how to prepare for your procedure, I encourage you to schedule a consultation to discuss your individual treatment plan.
References
1. Jayaram P, Yeh P, Patel SJ, et al. Effects of Aspirin on Growth Factor Release From Freshly Isolated Leukocyte-Rich Platelet-Rich Plasma in Healthy Men: A Prospective Fixed-Sequence Controlled Laboratory Study. Am J Sports Med. 2019;47(5):1223-1229. doi:10.1177/0363546519827294
2. Sok D, Raval S, McKinney J, et al. NSAIDs Reduce Therapeutic Efficacy of Mesenchymal Stromal Cell Therapy in a Rodent Model of Posttraumatic Osteoarthritis. Am J Sports Med. 2022;50(5):1389-1398. doi:10.1177/03635465221083610
3. Driver B, Marks DC, van der Wal DE. Not All (N)SAID and Done: Effects of Nonsteroidal Anti-Inflammatory Drugs and Paracetamol Intake on Platelets. Res Pract Thromb Haemost. 2020;4(1):36-45. doi:10.1002/rth2.12283
4. Kao DS, Zhang SW, Vap AR. A Systematic Review on the Effect of Common Medications on Platelet Count and Function: Which Medications Should Be Stopped Before Getting a Platelet-Rich Plasma Injection? Orthop J Sports Med. 2022;10(4):23259671221088820. doi:10.1177/23259671221088820
5. Parisien M, Lima LV, Dagostino C, et al. Acute Inflammatory Response via Neutrophil Activation Protects Against the Development of Chronic Pain. Sci Transl Med. 2022;14(644):eabj9954. doi:10.1126/scitranslmed.abj9954
Medical Disclaimer: This content is for educational purposes only and does not substitute for the medical advice of a physician. Always consult your healthcare provider before beginning any new treatment program. The information presented reflects the opinion of Dr. Jeffrey Peng and does not represent the views of his employers or affiliated hospital systems.
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