# How long each injection lasts *How Long Do Cortisone Shots Last? | Knee Injections Gilbert* > How long do cortisone shots last, and how long does a cortisone shot last in the knee? Plain timing details for cortisone, gel shots, and PRP. Here you’ll learn when cortisone, gel, and blood-based knee shots usually start helping and fade. ## Cortisone helps soonest during the early weeks Cortisone can start easing knee soreness within days. People often report the most relief during the first month and a half. By three months, cortisone usually adds much less pain relief. That means the early improvement has often begun to fade. At six months, studies found no clear pain difference between cortisone and a salt-water dummy shot. This doesn’t mean every person stops feeling relief then. Note the day walking first feels easier after your shot. Then write down when normal walking starts to bother you again. ## Gel starts slower and sometimes eases pain longer A gel shot contains hyaluronic acid, a substance in joint fluid that keeps it slippery and helps cushion the knee. Gel doesn’t ease soreness as quickly as cortisone. After about two months, people given gel sometimes reported less pain than those given cortisone. The catch is that the difference may feel too small to notice. A blood shot called PRP starts with a sample from you. The sample is spun so one small portion holds more platelets, which are tiny parts of blood. Some reviews of medical studies found PRP eased pain longer than other shots. One large study compared PRP with salt water and found no clear pain difference. Neither result tells you exactly how your knee will respond. Your earlier relief and current exam still matter. ## Your walking tells you whether relief matters Watch one daily task, such as standing from a chair. If that task gets easier, the change means something in your day. Call the treating office if relief never comes. Don’t wait if swelling or heat gets worse after the shot. Your earlier relief can’t predict the next result. QC Kinetix offers biologic therapies, meaning its medical providers prepare part of your blood at the clinic and place that prepared portion into your knee. ## Sources 1. The 2015 Cochrane review of 27 trials (1,767 participants) found intra-articular corticosteroid better than sham for knee OA pain (SMD -0.40, 95% CI -0.58 to -0.22; NNTB 8), but the benefit decayed with time: moderate at 1-2 weeks, small at 13 weeks, and no evidence of any effect at 26 weeks. All outcomes were graded LOW quality. Jüni P, et al. — [Intra-articular corticosteroid for knee osteoarthritis.](https://pubmed.ncbi.nlm.nih.gov/26490760/). *Cochrane Database Syst Rev*, 2015. DOI: 10.1002/14651858.CD005328.pub3. 2. A meta-analysis of eight RCTs found the pooled effect of intra-articular corticosteroid on knee pain was -0.58 SMD (95% CI -0.88 to -0.27; NNT 5.1), with the effect approaching statistical insignificance at four months and a non-significant pooled risk ratio for adverse effects of 0.95. Saltychev M, et al. — [The Magnitude and Duration of the Effect of Intra-articular Corticosteroid Injections on Pain Severity in Knee Osteoarthritis: A Systematic Review and Meta-Analysis.](https://pubmed.ncbi.nlm.nih.gov/31972612/). *Am J Phys Med Rehabil*, 2020. DOI: 10.1097/PHM.0000000000001384. 3. A meta-analysis of 7 trials (606 participants) mapped the crossover between the two commonest injections: corticosteroid is relatively more effective for pain from baseline to week 4, the two are equal at week 4, and beyond week 8 hyaluronic acid has the greater effect. Bannuru RR, et al. — [Therapeutic trajectory of hyaluronic acid versus corticosteroids in the treatment of knee osteoarthritis: a systematic review and meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/19950318/). *Arthritis Rheum*, 2009. DOI: 10.1002/art.24925. 4. A 2022 BMJ systematic review and meta-analysis of 169 trials (21,163 participants) found viscosupplementation produced only a small pain reduction versus placebo (SMD -0.08, 95% CI -0.15 to -0.02; about -2.0 mm on a 100 mm VAS), below the minimal clinically important difference, and trial sequential analysis indicated conclusive evidence of clinical equivalence with placebo since 2009. Pereira TV, et al. — [Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/36333100/). *BMJ*, 2022. DOI: 10.1136/bmj-2022-069722. 5. The RESTORE randomized trial (288 participants, leukocyte-poor PRP, 3 weekly injections) found no significant difference from saline placebo at 12 months in knee pain (-2.1 vs -1.8 points; difference -0.4, 95% CI -0.9 to 0.2) or in medial tibial cartilage volume (-1.4% vs -1.2%), with 29 of 31 secondary outcomes also showing no between-group difference. Bennell KL, et al. — [Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis: The RESTORE Randomized Clinical Trial.](https://pubmed.ncbi.nlm.nih.gov/34812863/). *JAMA*, 2021. DOI: 10.1001/jama.2021.19415. 6. A 2024 network meta-analysis of 48 studies (9,338 knees) at minimum 6-month follow-up ranked PRP first for pain and function (SUCRA 91.5), then BMAC (76.5) and hyaluronic acid (53.1), with corticosteroid (15.2) barely above placebo (13.7) at that time point. Jawanda H, et al. — [Platelet-Rich Plasma, Bone Marrow Aspirate Concentrate, and Hyaluronic Acid Injections Outperform Corticosteroids in Pain and Function Scores at a Minimum of 6 Months as Intra-Articular Injections for Knee Osteoarthritis: A Systematic Review and Network Meta-analysis.](https://pubmed.ncbi.nlm.nih.gov/38331363/). *Arthroscopy*, 2024. DOI: 10.1016/j.arthro.2024.01.037. 7. A double-blind RCT of 192 patients followed to a mean of 64 months found PRP did NOT provide superior clinical improvement over hyaluronic acid on any score at any follow-up point. Median duration of subjective symptomatic relief was 12 months for PRP and 9 months for HA (not significant). The only significant difference was a lower 24-month reintervention rate with PRP (22.6% vs 37.1%, P=.036). Di Martino A, Di Matteo B, Papio T, et al. — [Platelet-Rich Plasma Versus Hyaluronic Acid Injections for the Treatment of Knee Osteoarthritis: Results at 5 Years of a Double-Blind, Randomized Controlled Trial.](https://pubmed.ncbi.nlm.nih.gov/30545242/). *American Journal of Sports Medicine*, 2019. DOI: 10.1177/0363546518814532. 8. The GRASP factorial randomized trial (708 patients with rotator cuff disorders) found subacromial corticosteroid injection provided NO long-term benefit over 12 months, and progressive exercise was not superior to a single best-practice advice session with a physiotherapist. Hopewell S, et al. — [Progressive exercise compared with best practice advice, with or without corticosteroid injection, for the treatment of patients with rotator cuff disorders (GRASP): a multicentre, pragmatic, 2 × 2 factorial, randomised controlled trial.](https://pubmed.ncbi.nlm.nih.gov/34265255/). *Lancet*, 2021. DOI: 10.1016/S0140-6736(21)00846-1. 9. FDA's HCT/P guidance sets out the minimal-manipulation and homologous-use criteria that decide whether a human cell or tissue product is regulated solely under 21 CFR Part 1271 (section 361) or requires a biologics licence; cell-based orthopaedic injections that fall outside those criteria are unapproved drugs and biological products, and no cell-based product is FDA-approved to treat osteoarthritis. U.S. Food and Drug Administration — [Regulatory Considerations for Human Cells, Tissues, and Cellular and Tissue-Based Products: Minimal Manipulation and Homologous Use - Guidance for Industry and FDA Staff](https://www.fda.gov/regulatory-information/search-fda-guidance-documents/regulatory-considerations-human-cells-tissues-and-cellular-and-tissue-based-products-minimal). *U.S. Food and Drug Administration*, 2020. 10. A qualitative study interviewing 38 patients and 19 primary care clinicians found patients valued injections as an alternative to treatments they found undesirable, but reported wide variation in access, in onset and in how long the effect lasted; clinicians described an overarching theme of 'caution and competence', including uncertainty about the evidence and guidelines and the possibility of placebo. Moore AJ, et al. — [Intra-articular corticosteroid injections for osteoarthritis: A qualitative study of patients' and clinicians' experiences.](https://pubmed.ncbi.nlm.nih.gov/39441848/). *PLoS One*, 2024. DOI: 10.1371/journal.pone.0311668. ## An exam can answer what a page cannot Written information can describe common causes and care, but it can’t examine your knee. Bring medicine names, earlier records, and notes about movements that raise soreness. At the Chandler office, medical providers can examine the joint and answer your questions. You can then decide whether a clinic visit fits your needs. Book a free consultation: --- Clear answers about a sore knee and what comes next. Clear guidance on knee soreness, including its common causes, shot timing, warning signs, and non-surgical care near Gilbert. Plain information about knee soreness, common shot timing, warning signs, and care near Gilbert. This site is written and operated by the owners of the QC Kinetix clinics serving the Phoenix area, whose nearest office to Gilbert is on South Dobson Road in Chandler. There is no bystander here: the people reading the literature by the calendar are the same people who would book the appointment, and that is printed on every page rather than left for a reader to work out. Copyright 2026 The Gilbert Knee Clock. General education about a body of published research, not medical advice about a particular knee - only a clinician who can examine one can tell you about yours.