Pharmacists and environmental health experts have warned Nigerians against using expired medicines, saying they may lose their effectiveness and, in some cases, degrade into substances that can cause harmful effects.
The warning comes as concerns grow over the number of unused and expired medicines kept in Nigerian homes and the lack of clear systems for safely disposing of them.
Former President of the Pharmaceutical Society of Nigeria, Olumide Akintayo, told PUNCH Healthwise that the amount of active ingredient in a medicine can decline after its expiry date, depending on the drug and storage conditions.
He said this could reduce the medicine’s therapeutic effect, while in some cases degraded ingredients could become harmful to body organs.
The President of the Pharmaceutical Society of Nigeria, Tanko Ayuba, also warned in a March 15, 2025 interview with PUNCH Healthwise that expired medicines could lose potency and degrade into harmful compounds, potentially causing toxic effects such as organ damage or severe allergic reactions.
Ayuba said counterfeit and expired medicines pose serious risks because they can result in treatment failure, worsening illness and, in severe cases, death.
The problem extends beyond medicines still being used by patients. A study published in the Pan African Medical Journal on June 8, 2022, based on a survey of 534 respondents in Lagos State, found that 53% had some quantity of unused medicine at home. The study also found that 43.6% had between one and five unused or expired medicines at home, while 57.9% did not know what to do with unused or expired medicines.
The disposal pattern was also a concern. The study found that 73.2% of respondents threw unused medicines into household garbage, while 19.3% flushed unused medicines down toilets or sinks. Only 3.4% said they returned unused medicines to a pharmacy.
Environmental health experts say the danger does not end when an expired medicine leaves the home.
In a May 3, 2026 report by PUNCH Healthwise, Professor Olayinka Adewoye, an environmental health and toxicological risk assessment expert at Ladoke Akintola University of Technology, warned that pharmaceutical ingredients can persist after medicines are flushed or dumped.
Adewoye said active ingredients can move through soil and into groundwater, including wells and boreholes. He also linked improper disposal of antibiotics to antimicrobial resistance, saying trace amounts entering water, soil and food could contribute to the problem.
The World Health Organization advises against using medicines after their expiry dates. WHO guidance says expired medicines should be safely disposed of and not administered. It also warns that pharmaceutical waste needs to be properly managed to prevent environmental and public health risks.
WHO also advises consumers to check the expiry date, examine the condition of the packaging and avoid medicines that appear discoloured, degraded or have an unusual smell. Medicines should be obtained from trusted and licensed outlets.
For Nigeria, experts are calling for stronger systems for collecting unused and expired medicines from households. The 2022 Lagos study found that 88.9% of respondents supported a programme to retrieve unused, leftover or expired medicines.
Adewoye has called for dedicated collection and treatment centres for pharmaceutical waste, while the study’s researchers recommended community-based medicine take-back programmes.
The issue therefore goes beyond checking the expiry date before taking a tablet. It also raises questions about what happens to medicines after they are no longer needed and whether Nigerians have safe, accessible and affordable ways to return them.
For consumers, the safest approach is to avoid using expired medicines and seek advice from a pharmacist or other qualified health professional on how to dispose of them. WHO guidance also recommends avoiding the disposal of medicines on the ground or in rivers, sinks, drains or toilets.
