Fact-Check: No Scientific Evidence That Onion Juice Cures Human Conjunctivitis (Pink Eye)
An AI-generated photograph of an onion and a human eye. Credit: Meta AI
By Toheeb Babalola
CLAIM:
A TikTok video claimed that drinking onion juice and using it as an eyedrop would clear conjunctivitis in a human eye.
VERDICT:
Studies and specialists affirmed that raw onion juice is dangerous to the human eye and does nothing to cure conjunctivitis (pink eye), making the claim MISLEADING.
FULL TEXT:
A video, recently circulated on TikTok, shows a middle-aged woman with the username “Lizzy Remedy Herb” alongside displayed pictures of “Pink and Red Eyes” and the inscription “Onions Clear It.”
In a teaching style, she held two onions—red and white—and began narrating their traditional benefits in clearing conjunctivitis in human eyes.
She was telling her over 300k followers, in pidgin English, that “if your eyes dey bring water or dey red like this [display picture], all you need is red onion.”
The herbalist proceeded to inform them that they should peel, slice, and pour the red onion in a pot, then add water. She told them to boil it for at least five or ten minutes, and after it is ready, they should drink it for two weeks.
“By the grace of God, your eyes will clear,” she concluded on the red onion.
Caption: A screenshot of the TikTok video.
The woman, on the white onion, explained to the TikTok users to cut it into pieces and leave it inside a pot for 24 hrs to allow extraction of its natural juice.
She instructed them to “use the liquid and drop it on [your] pink eye. One drop in the morning and evening.”
Ending her one-minute session, saying that “I have been giving this remedy to people since last year. Go and check. Because of the new followers, I have to repeat it. Please share.”
As of the time of filing this report, the video has garnered 18.6k likes, 399 comments, and 15.8k shares and is still counting, the comment section, many users showered praises on the herbalist. While some users disagreed with the woman, preferring drinking the onion juice to using it as an eyedrop.
Caption: A screenshot of the comment section
Her claims remain hazy to them. Factcheck Africa fact-check the claim.
VERIFICATION:
Conjunctivitis, mostly called ‘pinkeye’, is an infection that turns the white area of the eyelid and eyeball red or pink, allowing small blood vessels in the membrane to become swollen and irritated.
It is caused by either a viral or bacterial infection. Both infections are contagious and could be traced to adenovirus, herpes simplex virus, and varicella-zoster virus. They spread through direct or indirect contact with the liquid that drains from the eye of someone who’s infected. One or both eyes may be affected.
Eye pain, feeling something is stuck in the eye, blurred vision, light sensitivity, itchiness and redness in one or both eyes, and nonstop discharge of tears in one or both eyes are all symptoms of conjunctivitis.
On the other hand, the onion, botanically known as Allium cepa, is a biennial vegetable plant grown for its edible bulb. It is in three different colours—yellow, red, and white—depending on the climate and where it is being cultivated. Despite this uniqueness, they are widely used as part of ingredients for preparing cuisine at homes.
When fresh onions get cut and kept for hours or days, a volatile oil would be naturally extracted—which is called ‘onion juice.’ This juice produces a pungent stench due to the release of enzymes called allinases, which convert amino acid sulfoxides to sulfenic acids. However, does it cure a pink eye?
A 1999 report revealed that the volatile liquid also produced a stinging sensation in the eyes of people nearby, triggering ‘uncontrollable tears’.
A 2024 quasi-experimental study conducted on the application of onion juice as eye drops for conjunctivitis showed that 59% [of the participants] experienced symptom decrease after the first use and 100% achieved full recovery after three applications. However, its self-reported methodology lacks rigorous laboratory and clinical trials, flagging the study as‘unreliable.’.
A 2024 study, conducted for animals, showed onion juice as having an inhibitory effect on the growth of microorganisms in the eye. But it requires ‘further investigation’ to treat eye infections, including conjunctivitis and blepharitis.
Some researchers see garlic and onion as potential antidotes to tackle antibiotic-resistant infections; they would be ‘mixed with other ingredients’.
Femi Dokun-Babalola, a professor of ophthalmology at the Faculty of Medicine, Bingham University, and medical director at Rachel Eye Center, said that there is no scientific evidence that onion juice cures conjunctivitis, confirming that onions contain sulphur compounds that may irritate the eyes and cause reflex tearing, but this is not the same as treating infection or inflammation. He noted that no peer-reviewed ophthalmology studies support the use of onion juice for curing conjunctivitis.
Dokun-Babalola said that applying raw onion juice to the eyes is not safe and can cause corneal damage or abrasions, which can increase the risk of secondary infection and exacerbation of the underlying condition, delaying proper treatment and healing.
“The eye is highly sensitive, and applying unsterile or caustic substances can lead to blindness. Traditional remedies are popular and sometimes culturally significant, but not all are safe for delicate organs like the eye.
People should also avoid urine, sugar water, and battery acid. All dangerous. They should seek medical attention early, especially if symptoms are severe (pain, discharge, decreased vision).” He concluded.
Catherine Ukponmwan, a professor and consultant ophthalmologist at the College of Medical Sciences, University of Benin, buttressed that “onion juice is very harmful and toxic to the eyes because, if applied, the eyes can develop infections such as endophthalmitis and corneal ulcers and become blind.”
She advised that people should never use any traditional remedies for treating the eyes. Adding that can lead to severe visual loss and blindness. “They should see a medical doctor or ophthalmologist for proper treatment.”
Speaking from experience, Dr. OrighoMisan Soleye, an optometrist at the State Specialist Hospital, Asubiaro, Osogbo, said she has encountered patients who developed cornea ulcers after carelessly applying onion juice into their eyes, causing them to require frantic medical attention. She emphasised that “what started as a simple conjunctivitis that could have been resolved with medication becomes a corneal ulcer that leads to vision loss.”
Soleye, in her decades of practice, confirmed that substances like onion juice, breast milk, etc., are not safe to be placed into the eye, reiterating that they are yet to be proven scientifically as solutions for conjunctivitis.
Also, Dr. Kizito Osuagwu, an optometrist at the June Hospital Dental Eye Clinic, stated that onion juice can give a ten-second relief from itchy eyes but does not clear conjunctivitis.
“Some patients (both literate and non-literate) presented with certain symptoms, and in between consultations they ‘confessed’ to using onion as a home remedy for the symptoms they noticed. There’s always a ‘redness’ effect from using onion juice on the eye, and instead of it having a positive/no effect, it turns out to worsen the situation.
“We optometrists have used radio jingles, online adverts, pictorial representations, and even ‘life’ examples to create awareness for the public on the dangers of traditional remedies,” Osuagwu said.
CONCLUSION:
Using onion juice as an eyedrop directly into a human eye could lead to loss of vision, and drinking it would trigger uncontrollable tears. Therefore, onion juice is unsafe and does nothing to cure conjunctivitis (pinkeye).
