What is hyaluronic acid for joints

Hyaluronic acid is a natural component of joint fluid and cartilage. It makes synovial fluid viscous and elastic, so the joint surfaces glide better. In osteoarthritis its concentration and molecular weight fall.

An intra-articular injection of sodium hyaluronate is called viscosupplementation, or “gel injection”. Products differ in molecular weight and structure: linear and cross-linked forms, a single injection or a course of 3–5 weekly shots.

Hyaluronic acid does not rebuild cartilage. Its purpose is to reduce pain and friction and improve joint function for several months.

Who is suited to hyaluronic acid injections

The method is mostly used for mild to moderate knee osteoarthritis when exercise and painkillers are not enough. The hip and ankle are treated less often, and there is less evidence for them.

Situation	Is hyaluronic acid suitable	Comment
Knee osteoarthritis stages I–III	Yes, most often	Moderate pain reduction for several months
Knee osteoarthritis stage IV	Limited	Weaker effect; joint replacement is also discussed
Marked joint swelling (synovitis)	Not immediately	The effusion and inflammation are treated first
Hip or ankle osteoarthritis	Sometimes	Only under ultrasound guidance; less evidence
Ligament or meniscus injury	No	Hyaluronic acid does not treat tears

When it starts working and how long it lasts

Unlike cortisone, hyaluronic acid does not act at once. Improvement is usually noticeable after 2–4 weeks, peaks after 1–2 months and can last up to 6 months.

The evidence is modest. A Cochrane review found pain reduction 5–13 weeks after a course; a meta-analysis in Annals of Internal Medicine rated the benefit as small. OARSI guidelines allow the method for knee osteoarthritis, especially when cortisone is contraindicated or has been repeated often.

Some patients respond well, others only minimally. If the first course brought no improvement, repeating it usually makes little sense.

What to do and avoid after the injection

On the day of the injection and the next day, go easy on the joint: more rest, no running, jumping or heavy lifting.
You can walk straight away. Cycling, swimming and normal activity are usually resumed after 2–3 days.
Mild pain, heaviness or slight swelling for 1–2 days is a normal reaction; cold for 15 minutes helps.
Postpone hot baths and saunas for 1–2 days.
If the joint swells a lot, becomes hot and red or you develop a fever, see a doctor urgently.

Contraindications and side effects

Contraindications

Skin infection at the injection site or joint infection. Allergy to hyaluronate. For products made from rooster combs: allergy to poultry or egg protein — products of bacterial origin are therefore used more often today. A large effusion is drained first.

Possible side effects

Pain, swelling or a feeling of heaviness in the joint for 1–2 days. Rarely, a marked inflammatory reaction with effusion, more often with cross-linked products. Very rarely, joint infection.

With caution

Anticoagulants are discussed with the physician in advance. Elective injections are usually postponed during pregnancy.

Hyaluronic acid, PRP or cortisone

Criterion	Hyaluronic acid	PRP	Cortisone
Principle	Improves the properties of joint fluid	Growth factors from your own blood	Strongly suppresses inflammation
Onset	2–4 weeks	2–6 weeks	1–3 days
Duration	up to 6 months	in studies up to 12 months, individual	weeks to 2–3 months
Evidence	Moderate benefit	In a meta-analysis of 18 trials better than hyaluronic acid at 6–12 months; some trials are neutral	Short relief; frequent shots are harmful
Frequency	Course 1–2 times a year	Course of 1–3 injections	No more than 3–4 times a year

A detailed comparison is on PRP or hyaluronic acid. Physicians sometimes combine both methods; the decision depends on the stage of osteoarthritis and the MRI.

How much does a hyaluronic acid course cost

In Germany, hyaluronic acid injections are usually paid by the patient. The price covers the product, the consultation and ultrasound guidance and is roughly €300–500 per injection: a course of 3–5 shots or a single injection of a high-molecular-weight product.

If you travel to Munich, clinic physicians may suggest a single injection of a long-acting product so that you do not have to come back every week. We tell you the exact cost in advance; general prices are on treatment cost.

Prices are approximate. Each clinic sets its own conditions and price: we send your request to several clinics and forward their offers so you can compare.

Recovery after the procedure

On the day of the injection you can walk and return to your hotel on your own. Intense load on the joint is best avoided for 1–2 days; ice helps with swelling. Then you gradually return to normal activity and exercise. The effect is assessed after 6–12 weeks; if there is no improvement, the clinic physician revises the plan.

Scientific evidence

Reviews and meta-analyses on the effectiveness of hyaluronic acid:

Bellamy N et al. Viscosupplementation for the treatment of osteoarthritis of the knee. Cochrane Database Syst Rev, 2006.
Rutjes AW et al. Viscosupplementation for osteoarthritis of the knee: a systematic review and meta-analysis. Ann Intern Med, 2012.
Belk JW et al. Platelet-Rich Plasma Versus Hyaluronic Acid for Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Am J Sports Med, 2021.

Frequently asked questions about hyaluronic acid

How long does hyaluronic acid take to work in the knee?

Usually 2–4 weeks, with the maximum effect after 1–2 months. There may be no relief in the first days after the injection — that is normal.

How long does the effect last?

Generally up to 6 months, less in some patients. The course is repeated once or twice a year if the first one helped.

What should I avoid after a hyaluronic acid injection?

For the first 1–2 days, avoid running, jumping, heavy lifting and saunas. You can walk straight away and resume normal activity after 2–3 days.

How many injections are in a course?

It depends on the product: one injection of a long-acting product or 3–5 injections at weekly intervals.

Does hyaluronic acid rebuild cartilage?

No. It improves the properties of joint fluid and reduces pain, but does not grow new cartilage.

Which is better for knee osteoarthritis: hyaluronic acid or PRP?

In a meta-analysis of 18 randomised trials PRP gave better results at 6–12 months, though not in every study. The choice depends on the stage of osteoarthritis and is made by the clinic physician.

Can you be allergic to hyaluronic acid?

Rarely. Products made from rooster combs are not used in people allergic to poultry or egg protein — products of bacterial origin are available for them.

How much does a hyaluronic acid injection cost in Germany?

Roughly €300–500 per injection, depending on the product and ultrasound guidance. We tell you the exact amount before booking.

How does RegenPAS organise treatment?

RegenPAS is a patient service centre in Munich, not a clinic. We review your images and symptoms and send a request to several partner clinics at once. Clinics that can accept you send their own conditions and price; prices differ between clinics, and you choose the option that suits you. The coordinator replies within 24 hours, and a clinic physician’s preliminary opinion follows in 1–3 business days. We then arrange the appointment, visa invitation, interpreter, transfers and accommodation. Treatment decisions are made by the clinic physician. Contact a coordinator.

Find the right injection treatment

Send your MRI or X-ray and tell us which injections you have already had. The coordinator replies within 24 hours; a clinic physician will suggest a suitable method.

Send request

+49 160 573 6643