Intravenous (IV) infusion is the most common method. Cells are suspended in saline and infused through a vein, usually in your arm, over 30–60 minutes. The procedure feels like receiving a blood transfusion—you sit comfortably, a nurse inserts an IV line, and the infusion runs. You're monitored for vital signs; most clinics observe you for 1–2 hours post-infusion to check for adverse reactions (rare). Advantages: non-invasive, painless, suitable for systemic conditions (neurological disease, autoimmune conditions). Disadvantage: cells circulate systemically; only a fraction reach target tissue. Recovery is immediate; you can leave the clinic the same day.
Intramuscular or subcutaneous injection targets muscle or tissue directly. A physician uses ultrasound or X-ray guidance to locate the target area (often a joint or damaged muscle) and injects cells in cell culture medium directly into tissue. The procedure takes 15–30 minutes. Local anaesthetic is applied, so pain is minimal. You might feel pressure or a brief stinging sensation. Advantage: cells are delivered directly to the problem area, maximising local concentration. Disadvantages: requires precise placement, possible bruising, local inflammation for 24–72 hours. Recovery is usually same-day, but you'll restrict activity in the injected area for 5–7 days.
Intra-articular injection: A subset of joint injection. Cells are delivered into the joint space (knee, hip, shoulder, etc.). Procedure is similar to receiving a steroid injection into a joint—common and relatively straightforward. Ultrasound guides needle placement. Local anaesthetic reduces pain. Advantage: direct local delivery for joint arthritis. Disadvantage: if infection occurs, it's in the joint; serious. Recovery is same-day, but joint immobilisation (strapping, reduced movement) is advised for 5–7 days.
Intrathecal delivery: Cells are injected into cerebrospinal fluid (CSF) surrounding the spinal cord. This is the most invasive method and is used for spinal cord injury, some neurological conditions, or severe autism cases. The procedure requires: (1) Local anaesthetic or twilight sedation, (2) Lumbar puncture (needle inserted between lumbar vertebrae), (3) Injection of cells into CSF, (4) Overnight hospital observation. Advantages: direct central nervous system delivery, highest brain/spinal concentration. Disadvantages: invasive, infection risk (though rare with sterile technique), possible side effects (temporary headache, back pain, nerve irritation). Recovery is 2–3 days; you'll rest, avoid heavy activity, and stay hydrated. Many clinics recommend bed rest for 24 hours post-procedure.
Topical application: For skin conditions, cells might be applied topically (directly onto the skin surface) or in a scaffold (a biodegradable matrix carrying cells). Procedure is non-invasive; cells are spread or applied like a dressing. Advantage: painless, no systemic effects. Disadvantage: only suitable for superficial conditions. Recovery is immediate.
Aeroolised delivery (inhalation): For lung or systemic conditions, cells might be nebulised and inhaled. This is experimental and less common. You inhale cells from a nebuliser (like asthma inhaler treatment). Advantage: direct lung delivery without IV or injection. Disadvantage: cell viability during aerosolisation is variable; still experimental. Recovery is immediate.
Combination approaches: Some protocols use multiple routes—e.g., IV infusion plus local joint injection—to maximise effect. This increases cost and procedural time but might improve outcomes in certain conditions.
Method selection: Your condition and clinic determine the method. The clinic will explain which is appropriate and why. Ask: "Why this method for my condition? Are there alternatives?" Credible clinics can justify their choice with evidence or reasoning.
Timing of effects: Methods are not equal in speed. IV infusion might show systemic benefits over weeks to months. Local injections might show local benefits faster (sometimes within days or weeks). Intrathecal delivery might take weeks to months for central nervous system effects to manifest. Discuss expected timelines with your clinic.
Procedural discomfort: IV is painless. Joint or tissue injections are usually painless with anaesthetic but might cause 24–72 hour post-procedure soreness. Intrathecal is the most uncomfortable but anaesthetic or sedation mitigates this.
Infection risk: IV and topical have minimal infection risk (sterile needle, short exposure). Joint injections carry low risk but serious if infection occurs. Intrathecal carries slightly higher risk but remains rare with strict sterile protocols. Ask your clinic about their infection prevention measures.
Post-procedure restrictions: IV requires only rest for a few hours. Local injections require 5–7 days of activity modification in the injected area. Intrathecal requires 1–2 days of bed rest and careful activity restriction for a week.
Cost: Methods vary in procedural cost. IV is simplest (€1,500–2,500). Joint or muscle injection is slightly more (€2,000–3,500). Intrathecal is most expensive (€3,500–6,000) due to hospital environment and anaesthesia.
Your role: On procedure day, ask questions before you sign consent. Clarify the method, expected discomfort, recovery timeline, and restriction period. Knowing what to expect reduces anxiety and improves compliance with post-procedure guidance.
Sources & further reading
Educational guide; most uses are investigational — consult a qualified physician. Reviewed by the StemCellAtlas editorial team.