Zinc supplements are a group of dietary supplements used for treatment of various conditions. Most notable zinc supplements are zinc acetate and zinc gluconate lozenges.
Both of these are used as zinc for colds remedies1.
With that in mind, how safe is to use zinc for treatment of colds? And how should you use it?
At the moment, there is lack of data and insufficient evidence that zinc can be used as a preventive to reduce the likelihood of a cold.
However, there is enough evidence to show that zinc supplements are effective in treating the common cold 2. However, there are a couple of cases when using supplements by mouth has caused adverse effects like nausea and bad taste.
Table of Contents
What the science says
Being that we always want to find a proof for any claim, whether it is zinc for cold or any other remedy, let’s take a look at what the science has managed to prove in the past several years.
The first time zinc was mentioned as a remedy for cold was in 1984, when a study showed that zinc supplements kept people from getting as sick. Since then, there have been mixed results regarding zinc and cold.
Most colds are caused by a type of virus called rhinovirus, which thrives and multiplies in the nasal passages and throat. Zinc works by preventing the rhinovirus from multiplying.
Zinc is more effective when taken in lozenge or syrup form, allowing the substance to stay in the throat and come in contact with the virus.
In 2016, a meta-analysis of zinc acetate lozenges and the common cold showed that taking supplements reduced the duration of the cold by 2.7 days 3.
The estimate was compared with the 7 days average duration of colds.
Another study, this one from 2013, found out that zinc supplements in doses of 75mg per day, taken 24 hours of the onset of cold symptoms, can reduce the average duration of cold symptoms by one day 4.
Additionally, individuals taking supplements were less likely to experience cold symptoms 1 week after the initial symptoms.
A study conducted in 2015, however, found no difference in the effects of zinc acetate lozenges on diverse respiratory symptoms 5.
There were some effects in terms of reducing nasal congestion, sneezing, and sore throat, but nothing on duration of headache and fever.
In 2012, a systematic review suggested that zinc formulations may shorten the duration of symptoms of the common cold. The review, however, suggested that further research was also needed 6.
How much zinc is safe?
As mentioned previously, some studies and cases have shown that zinc lozenges can cause adverse effects, including a bad taste. However, there was never long term damage.
Most of the adverse effects are caused by specific lozenge compositions and do not reflect the effect of zinc for cold.
With that in mind, the most recent trial on zinc dosage showed that 92mg dosage of zinc per day is more than enough to help you reduce the symptoms of cold 7.
It is also worth noting that in 2009, the US Food and Drug Administration issued a warning, stating that people should not use nasal sprays containing zinc 8.
How zinc helps
Zinc is an essential mineral in our body. That means that our body does not produce zinc, but needs it. A couple of systems, including the immune system, the endocrine system, and the reproductive system all need zinc in order to function properly.
If you are not taking enough amounts of zinc, you might suffer from depression, skin problems, neurological problems, hair loss, and much more.
Taking too much zinc, on the other hand, can cause other medical disorders. Zinc toxicity is a well-known medical conditions 9.
The Institute of Medicine’s Food and Nutrition, recommends upper intake of zinc for healthy adult men and women at 40mg per day.
That is the tolerable upper level, which is the maximum amount of a nutrient a human can consume without suffering side effects.
For children between 9 and 13 years old, the upper limit is 23mg per day and adolescent teenagers should not consume more than 34mg per day.
As mentioned previously, zinc can help your body fight off cold by preventing the virus to multiply.
Taking zinc supplements is one way of treating cold, but you can also up your consumption of foods high in zinc.
Those zinc rich foods include beef, shellfish, chicken, cheese, milk, kidney beans and oysters.
What you need to know about zinc and common cold?
You can treat, but not prevent cold
If you pop zinc supplements within 24 hours of the start of the symptoms, you can reduce the duration of the symptoms.
However, you cannot and should not take zinc supplements in a way to prevent cold. And the dosage should be 75mg, or three or four lozenges per day. Take them as long as the cold lasts.
Do not go for a spray
As mentioned previously, in 2009, the FDA warned against using zinc gel sprays and nasal sprays for cold. The FDA received more than 130 reports of people claiming zinc nasal sprays caused them to lose sense of smell.
While zinc is still available as a throat spray, do not use it. Always go for lozenges, and make sure to suck them, not crunch them. Lozenges need to dissolve slowly in order to be effective.
Not all lozenges are equal
One lozenge needs to contain between 13 and 23mg of zinc in order to be effective. You should know that not all lozenges contain that much amount.
Some brands contain little to no zinc in their lozenges. Read the label to see whether the lozenges will be effective or not.
Lozenges are not candy
We mentioned previously that the upper tolerable limit for adults is 40mg per day. Now, taking lozenges means that you will definitely exceed that limit.
But limit yourself to just three to five days, or roughly the average length of a cold. If you continue popping lozenges like they are candy, you might experience symptoms of zinc toxicity.
Consume one lozenge every three or four hours if you are sick. For healthy adults, limit yourself to just one per day.
Notable zinc benefits
There are many benefits of zinc, which is why it is an essential nutrient. As mentioned previously, zinc plays a role in many critical systems of our body.
Not only it treats cold, regular consumption of zinc from food sources can have a number of benefits for our body.
- Increase immune system
- Act as a powerful antioxidant, and prevent and help fight off cancer
- Balance hormones in our body
- Play an important role in hormone production, including increasing testosterone naturally
- Fight diabetes
- Balance insulin hormone, the main hormone involved in regulation of blood sugar
- Maintain heart health and support healthy blood vessels
- Prevent diarrhea and other digestive problems