Hyaluronic acid injections, sometimes called hyaluronan injections or viscosupplementation, are used mainly for osteoarthritis, and have also been investigated for several tendon problems including Achilles and rotator-cuff tendinopathy and tennis elbow. I want to be straight with you about what they can and cannot do. The evidence is most extensive for knee osteoarthritis, yet even there the average benefit over a placebo injection is small, and national guidelines disagree about whether it should be offered at all. Hyaluronic acid is a symptom-management option. It has not been shown to regenerate cartilage, reverse arthritis or reliably heal a damaged tendon.
Hyaluronic acid can help some people, but it is not a cure and the average advantage over placebo is modest. I only suggest it after the basics (exercise, load management, weight where relevant) have had a fair go, and always as a support to rehabilitation rather than a replacement for it.
What is hyaluronic acid?
Hyaluronic acid (HA) is a substance that occurs naturally in your joint fluid and connective tissues. Laboratory research suggests that an injection may improve the lubricating and shock-absorbing properties of joint fluid, influence pain and inflammatory signalling, alter some of the enzymes involved in tissue breakdown, and reduce friction around a tendon when placed in the surrounding tissue. These mechanisms are biologically plausible, but plausibility is not the same as proof that an injection will make a meaningful difference to how you feel.
It is also important to know that HA products differ considerably in molecular weight, concentration, cross-linking, volume and injection schedule. Results from one preparation should not be assumed to apply to every product on the market.
Hyaluronic acid for knee osteoarthritis
Evidence: extensive research, but average benefit over placebo is small
Knee osteoarthritis has by far the largest evidence base. Some trials report improvements that begin several weeks after treatment and last for several months, but much of that improvement also happens after a placebo joint injection. A large 2022 BMJ systematic review of 169 trials and more than 21,000 participants found that, in the best placebo-controlled studies, HA improved pain by about 2 points on a 100-point scale compared with placebo. That was statistically detectable, but smaller than the difference generally considered clinically important.
Because the same evidence can be read in different ways, the guidelines disagree:
- NICE recommends that hyaluronan injections should not be offered for osteoarthritis, finding no convincing improvement in pain, function or quality of life.
- The American Academy of Orthopaedic Surgeons does not recommend HA for routine treatment of symptomatic knee osteoarthritis.
- OARSI conditionally supports it for some people with knee osteoarthritis.
- A 2024 European expert consensus supports considering it in selected patients, particularly milder disease or where medication options are limited.
So where might it still be worth a conversation? Where local guidance and the product licence allow, I might discuss HA when exercise and weight management have been tried, symptoms are still limiting your rehabilitation or daily life, anti-inflammatory medication is unsuitable, a corticosteroid injection is undesirable or has not helped enough, and you understand that the average advantage over placebo is small and the aim is temporary relief rather than cartilage restoration. I would never present it as a routine treatment or a proven way to avoid a knee replacement.
Where else has it been studied?
Achilles tendinopathy
Evidence: limited, mainly one small comparative trial
The evidence for Achilles tendinopathy is much less developed. The most cited randomised trial involved 62 adults with midportion Achilles tendinopathy and compared two peritendinous HA injections with three sessions of shockwave therapy, with HA producing better pain and function scores up to six months. Encouraging, but it was small, had no placebo-injection group, and changed its primary outcome during the study. It does not show that HA beats a progressive tendon-loading programme. I would only consider it as a specialist add-on when the diagnosis is secure, an appropriate loading programme has been tried, symptoms remain substantially limiting, and the injection is placed around, not into, the tendon. It is not a licence to return straight to running or jumping.
Rotator-cuff tendinopathy
Evidence: conflicting and highly heterogeneous
Several trials have looked at HA for rotator-cuff-related shoulder pain, using different products, doses and injection sites. A 2023 systematic review of 18 studies (1,773 shoulders) found some comparisons favouring HA, but the results against placebo and corticosteroid were inconsistent. A 2025 review found no consensus on the best preparation, dose, location or schedule, and a recent clinical guideline described the true treatment effect as unclear. HA may be a steroid-sparing option for selected patients, but it has not been shown to outperform a well-designed exercise programme and should not replace rehabilitation.
Thumb-base (CMC joint) osteoarthritis
Evidence: weak, no clear superiority over placebo
HA is sometimes injected into the first carpometacarpal joint for thumb-base arthritis. However, a 2023 network meta-analysis of 446 patients found that no injection, including HA, was clearly better than placebo for short-term pain, and none clearly improved function. The American College of Rheumatology conditionally recommends against HA here, and NICE advises against hyaluronan for osteoarthritis generally. The preferred first approach stays: education and activity modification, hand exercises, a suitable thumb-base splint, and topical medication where appropriate. HA may occasionally be discussed as a self-funded specialist option, with the honest caveat that a clinically important benefit has not been established.
Tennis elbow
Evidence: few good-quality controlled studies, investigational
HA has also been injected around the common extensor tendon for persistent tennis elbow. A 2024 systematic review of seven studies found outcomes generally improved, but only three were comparative randomised trials, several were uncontrolled case series, and protocols varied widely. The review saw a possible trend towards better pain and function but could not make a firm recommendation, and earlier work suggested any advantage over a saline injection may be smaller than a clinically important difference. So HA stays a specialist or investigational option here, not a routine treatment. Load modification and progressive wrist-extensor, grip and upper-limb rehabilitation remain the foundation of care.
The evidence at a glance
| Condition | Current evidence | Likely clinical role |
|---|---|---|
| Knee osteoarthritis | Extensive research, but average placebo-controlled benefit is small and guidelines disagree | Selected use after shared decision-making; not recommended routinely by NICE |
| Midportion Achilles tendinopathy | Mainly one small comparative randomised trial | Possible add-on to loading rehabilitation |
| Rotator-cuff tendinopathy | Several trials, but conflicting and highly heterogeneous | Specialist steroid-sparing option with uncertain benefit |
| Thumb-base (CMC) osteoarthritis | Limited evidence without clear superiority over placebo | Not routinely recommended |
| Tennis elbow | Few good-quality controlled studies | Experimental or specialist add-on to rehabilitation |
Does ultrasound guidance matter?
As a sonographer, I use ultrasound for these injections because it lets me confirm the target, spot an effusion, a significant tear or an alternative diagnosis, enter a small or awkward joint accurately, place HA around a tendon rather than into it, and steer clear of nearby nerves and blood vessels. What ultrasound does not do is change the underlying evidence: more accurate placement improves my confidence that the injection went where intended, but it does not guarantee that HA itself will work better. In practice a knee can often be injected accurately without ultrasound, whereas guidance is genuinely valuable for small joints and for placing fluid around a tendon.
How many injections are needed?
There is no universal regimen. Depending on the product and the condition, studies have used a single injection, two injections about a week apart, or a course of three or more. Because preparations are not interchangeable, I will always explain the specific product, dose and proposed schedule before we go ahead. The evidence does not crown one regimen as best across all conditions.
Is hyaluronic acid safer than a steroid?
HA avoids the steroid-specific effects such as skin depigmentation, local fat atrophy, a temporary rise in blood sugar and potential effects on tendon cells. That does not make it risk-free.
- Temporary pain or swelling after the injection
- Bruising or bleeding
- A short-lived inflammatory flare
- A more severe inflammatory or "pseudoseptic" reaction (uncommon)
- Infection (rare, but potentially serious)
- Allergic reaction to a component of the preparation
- Injury to a nearby tendon, nerve or blood vessel
Seek urgent medical advice if an injected area becomes increasingly painful, hot, red or swollen, especially with fever or feeling unwell.
Questions worth asking before treatment
Before any HA injection, it is reasonable to make sure you understand:
- What diagnosis is being treated?
- Is the injection into the joint or around a tendon?
- Is this use covered by the product's licence?
- Which HA product and schedule will be used?
- What improvement is realistically expected?
- What are the alternatives?
- What rehabilitation is needed afterwards?
- What happens if it does not help?
Peritendinous treatment for Achilles, rotator-cuff or elbow tendinopathy may fall outside the licensed indication of some HA products. I will always make that clear as part of consent.
A sensible treatment pathway
The sequence I follow is straightforward: confirm the diagnosis and rule out another cause of pain; start condition-specific education, activity modification and rehabilitation; use established treatments such as exercise, weight management, splinting or suitable medication where relevant; reassess if progress is limited; and only then consider HA, when the remaining symptoms justify the cost, inconvenience and small procedural risk. We would discuss the specific, and sometimes conflicting, evidence for your condition, and you would continue progressive rehabilitation afterwards rather than relying on the injection alone, with a review against agreed pain and functional goals.
The key message
Hyaluronic acid has been studied most extensively for knee osteoarthritis, but its average benefit over placebo is small and NICE does not recommend routine use. The evidence for Achilles and rotator-cuff tendinopathy, thumb-base osteoarthritis and tennis elbow is weaker still. HA can be a reasonable specialist or steroid-sparing option for selected people, but it should be offered with realistic expectations, and it should support your rehabilitation, never replace it.
Frequently asked questions
Does hyaluronic acid regrow cartilage?
No. There is no good evidence that HA regenerates cartilage or reverses arthritis. It is a symptom-management treatment aimed at temporary relief.
Is it better than a steroid injection?
Not clearly. A steroid often gives faster short-term relief; HA may last a little longer for some people and avoids steroid-specific side effects. For many conditions neither has a large, reliable advantage over placebo, which is why I treat both as adjuncts to rehabilitation.
Will it help me avoid a knee replacement?
It should not be presented that way. HA has not been shown to prevent or reliably delay joint replacement.
How soon will I know if it worked?
Any benefit typically builds over several weeks. We agree in advance what improvement would count as success, and review against that.
Do you offer hyaluronic acid at Insight MSK?
Yes, as an ultrasound-guided option in selected cases, after the basics have been tried and once we have discussed the realistic, evidence-based expectations for your specific condition.
References
- Pereira TV, Juni P, da Costa BR, et al. Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis. BMJ. 2022;378:e069722.
- NICE. Osteoarthritis in over 16s (NG226): rationale and impact (intra-articular hyaluronan not recommended). 2022.
- American Academy of Orthopaedic Surgeons. Management of Osteoarthritis of the Knee, 3rd edition, clinical practice guideline.
- Randomised trial of peritendinous hyaluronic acid versus shockwave for midportion Achilles tendinopathy. PubMed 27639439.
- Systematic review of hyaluronic acid for rotator-cuff-related shoulder pain, 2025. PubMed 40093995.
- Network meta-analysis of injections for thumb-base (first CMC) osteoarthritis, 2023. PMC10587673.
- Systematic review of hyaluronic acid injections for tennis elbow, 2024. Full text (PDF).
This page provides general information only. It cannot diagnose your individual problem or replace assessment and advice from a qualified healthcare professional.