Consumer Safety Articles
Report suspected side effects from medicines to your healthcare professional
2 November 2026
Audiences
Consumer
Healthcare professional
Product-type
Therapeutic Products
Medicines must be evaluated by the Health Sciences Authority (HSA) to ensure that they meet the appropriate safety, quality and efficacy standards before they are approved for use in Singapore.
Information about the safety and efficacy of a new medicine undergoing evaluation is mainly obtained from animal studies and clinical trials. Clinical trials usually involve a relatively small number of patients (about 3,000 trial subjects) and specific populations. Some side effects of a new medicine may only become apparent after it has been approved and used over longer periods across larger, more diverse populations.
It is therefore important to continually monitor for the safety of medicines. One of the ways HSA identifies potential safety issues is by monitoring side effects reported by healthcare professionals and pharmaceutical companies.
What are side effects?
Side effects are unwanted effects that occur after taking a medicine. Different people can react differently to medicines. Whether they experience side effects, and how these affect them, will depend on factors such as:
Dose of the medicine
General health, age and gender
Concurrent treatments or use of other medicines or health products [including Chinese Proprietary Medicines (CPMs), health supplements or traditional medicines]
Most side effects are mild and can resolve on their own. For instance, antibiotics may cause diarrhoea, which resolves on its own after treatment ends. Other side effects can be managed with simple measures such as taking fever and pain medicines (e.g. ibuprofen, diclofenac and aspirin) after food to reduce stomach discomfort.
However, some side effects can be more serious and may require medical attention. These include life-threatening effects, such as anaphylaxis, a serious allergic reaction, liver damage, and severe kidney injury.
Additionally, some side effects may appear suddenly (e.g. skin allergies), while others develop gradually or only after long-term use (e.g. brittle bones from prolonged steroid use). Some may be clearly noticeable (e.g. skin rash), while others are ‘silent’ and are only detected through blood tests (e.g. abnormal liver function tests).
What should I do?
Report side effects to your healthcare professional
If you suspect that you are experiencing a side effect, inform your healthcare professional. Provide information on the name, dose, and duration of the medicine taken, details of the suspected side effect, concurrent medicines (including health supplements and TCM) and any other medical conditions that you have.
Your healthcare professional can assess whether the symptoms may be related to the medicine and, where appropriate, report the suspected side effect to HSA for further monitoring and review.
Your healthcare professional would also be in the best position to advise if you need any adjustments to your current treatment.
Misconceptions on reporting of side effects
Here are some common misconceptions about reporting suspected side effects from medicines to your healthcare professional:
Myth #1: “This side effect will go away by itself, let’s wait and see.”
Truth: Even if a side effect appears to resolve by itself, it is advisable to still inform your healthcare professional to ensure you get the medical attention you need.
Myth #2: “Reporting my side effect does not matter, one person’s experience will not cause any change.”
Truth: HSA monitors every report it receives, and a well-documented case can make a difference to our decision if a safety issue needs any regulatory actions.
Myth #3: “I don’t wish to be seen as complaining or fussing over my medication.”
Truth: Raising concerns about how medicines make you feel is acceptable, and is part of self-care. You may also be helping your healthcare provider to do their job better.
What happens after your healthcare professional reports to HSA?
The report submitted by your healthcare professional helps HSA identify and investigate any potential safety issues arising from the use of a medicine, such as previously unknown side effects or product quality issues. HSA studies these reports to determine whether the benefits of the medicine continue to outweigh the risks, and assesses if any action needs to be taken. HSA’s regulatory actions may include communicating these risks to the public and strengthening product package information.
Every side effect report helps to make medicines safer for everyone.
Report to your healthcare professional because it matters!
