The UK weight-loss medication landscape now includes both injectable and oral options. Understanding the advantages and disadvantages of each format can help you and your prescriber choose the right approach.
Injectable Medications Available in the UK
- Mounjaro (tirzepatide): Once-weekly injection, dual GIP/GLP-1 agonist.
- Wegovy (semaglutide 2.4 mg): Once-weekly injection, GLP-1 agonist.
- Saxenda (liraglutide 3 mg): Once-daily injection, GLP-1 agonist.
Oral Medications Available in the UK
- Orlistat (Xenical/Alli): Fat absorption inhibitor, taken with meals.
- Oral semaglutide (Rybelsus): GLP-1 agonist in tablet form, currently licensed for type 2 diabetes but sometimes prescribed off-label.
Pros of Injectable Medications
- Superior efficacy: Injectables like Mounjaro and Wegovy deliver significantly greater weight loss than any currently available oral option.
- Less frequent dosing: Once-weekly injections reduce the daily burden of remembering medication.
- Bypasses the gut: Subcutaneous delivery avoids first-pass metabolism in the liver and is not affected by food timing.
- Consistent absorption: Injection ensures predictable drug levels regardless of diet or digestive issues.
Cons of Injectable Medications
- Needle anxiety: Some patients find self-injection daunting, although modern pre-filled pens make it straightforward.
- Storage requirements: Most need refrigeration before first use.
- Cost: Injectables are generally more expensive—Mounjaro costs £150–£300/month versus £30–£80/month for Orlistat.
- Sharps disposal: Used pens must be disposed of in approved sharps bins.
Pros of Oral Medications
- No needles: Simply swallow a tablet—preferable for those with needle phobia.
- Lower cost: Orlistat, the most common oral option, is available over the counter from around £30/month.
- Easy storage: No refrigeration needed.
- Wider availability: Orlistat can be purchased without prescription (at the lower 60 mg dose).
Cons of Oral Medications
- Lower efficacy: Orlistat produces modest weight loss (3–5%) compared to injectables (15–22%).
- Frequent dosing: Up to three times daily for Orlistat; oral semaglutide requires strict fasting protocols.
- Unpleasant side effects: Orlistat’s oily stools and flatulence are a common reason for discontinuation.
The Future: Oral GLP-1 Agonists
Pharmaceutical companies are actively developing oral versions of GLP-1 and dual-agonist medications that may eventually match the efficacy of injectables. Oral semaglutide at higher doses has shown promising weight-loss results in trials. If these reach the UK market at competitive prices, the gap between oral and injectable options could narrow significantly in the coming years.
Making Your Decision
The best format depends on your weight-loss goals, budget, tolerance for injections and medical history. Discuss all options with your prescriber and use MedsLens to compare prices across UK pharmacies for whichever treatment you choose.