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Zinc Benefits, Side Effects & Safety Information

Published: 13th May 2018. Last updated: 21th July 2019.

Shaun Ward MSc ANutr

Staff Writer


Zinc is the second most abundant trace metal in the body and is needed for many different metabolic functions.

It is an essential cofactor for over 300 enzymes and 1000 transcription factors.

Some of its major roles is to aid cell signaling, neuronal activity, DNA replication, and transcription regulation.

Due to its crucial metabolic role, a zinc deficiency is heavily linked to growth retardation, male hypogonadism, neurodegenerative conditions, and impaired wound healing and immune health.

Foods high in zinc include shellfish, meat, poultry, fish, nuts and seeds, dairy, eggs, wholegrains, and certain vegetables.

The Different Types Of Zinc Supplements

Although zinc can be consumed in adequate amounts through the diet, some people opt for supplementation to reach their recommended daily amounts.

Zinc supplements come in many different forms:

  • Zinc gluconate: The most common over-the-counter form of zinc. It is often found in lozenges and nasal sprays.
  • Zinc acetate: Often added to certain types of cold lozenges.
  • Zinc sulfate: Used in a lot of research on treating acne.
  • Zinc picolinate: This type of zinc is speculated to have superior absorption to other forms.
  • Zinc orotate: This form is bound to orotic acid and is becoming increasingly popular.
  • Zinc citrate: A well-absorbed form of zinc but with a less bitter taste.

The Potential Benefits of Zinc

Below is a list of every potential benefit that's backed by credible scientific research:

It May Improve Sleep Quality

Sleep is defined as a natural periodic state of rest, in which the eyes remain closed and consciousness is completely or partially abolished, so that there is a decrease in bodily movement and responsiveness to external stimuli.

Interestingly, the concentration of zinc in the blood zinc if highly correlated with sleep duration and sleep quality [1].

Zinc has been shown to aid the onset of sleep in healthy and malnourished infants, allowing them to sleep an extra ~1.5 hours a day on average [2].

In elderly patients with insomnia, a mineral supplement (melatonin, magnesium and zinc) resulted in a remarkable ~100% improvement of sleep quality based on the ‘Pittsburgh Sleep Quality Index’ [3].

In large-scale population studies, individuals treated for 3 months with daily zinc supplements demonstrated an improved sleep onset latency and sleep efficiency compared to control subjects [4].

However, one of the key issues with zinc research is that it is rarely supplemented alone, and so it is hard to isolate its effects outside of the different compounds being supplemented alongside it. This is especially important when melatonin is one of the other supplements often used, which has a great amount of research showing its clear benefits on effect on sleep [5].

Despite this, it does seem as though zinc is having its own effect on sleep, likely due to acting on specific compartments of the central nervous system and activating signaling pathway which promote sleep.

It May Improve Immune Function

As zinc is necessary for immune cell function and cell signaling, a deficiency can quickly lead to a weakened immune response.

This is a big reason why many over-the-counter medications and natural remedies incorporate zinc into their “immune boosting” products.

Zinc can support the immune system as an antioxidant, anti-inflammatory, and may be able to stimulate particular immune cells to reduce oxidative stress.

A scientific review concluded that consuming zinc within the immediate period when a common cold starts is able to significantly reduce the duration of symptoms by an average of one day [6].

Zinc has also been targeted as a key nutrient needed to prevent diarrhea, as it not only helps to maintain the immune system but also supports intestinal mucosal cell transport [7].

It May Improve Wound Healing

Zinc plays critical roles in wound healing, such as collagen synthesis, immune function and inflammatory responses.

In fact, zinc is commonly used in hospitals as a treatment for burns and other serious skin conditions [8].

For example, in a 3 month study on people with foot ulcers, individuals taking 200mg of zinc per day experienced significant reductions in ulcer size compared to a placebo group [9].

How To Take Zinc?

The recommended daily zinc intake is 11mg for men and 8mg for women. However, slightly higher doses may be required to treat certain conditions such as acne, diarrhea, and insomnia.

If you are going to take a supplement, the amount required is based on the amount of bioavailable zinc (elemental zinc) within a certain form of product.

For example, zinc sulfate contains ~25% elemental zinc, so people would have to calculate how to reach their recommended daily amount based on the total weight of a product or tablet.

It is always recommended to stick to the instructions on the label before taking a zinc supplement and consult your doctor if needed.

Zinc Safety And Side Effects

Zinc is generally tolerated very well and is not associated with safety concerns at the recommended dosages.

However, high doses have been associated with adverse side effects including [10]:

  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach pain

In addition, going beyond ~40mg per day of elemental zinc may lead to fever, coughing, headaches, and fatigue [11].

Keep in mind, zinc can also interfere with your body’s ability to absorb copper, which may cause long-term issues with copper metabolism if zinc intake is too high.


Zinc is an extremely common mineral within the body and is needed for many different metabolic functions such as cell signaling, neuronal activity, DNA replication, and transcription regulation.

Deficiencies in zinc are a current public health issue, as over time it may cause neurodegenerative conditions and impair wound healing and immune health.

Some evidence suggests zinc supplementation may help with sleeping conditions, wound healing and immune function. However, improvements in these areas cannot be guaranteed as zinc is rarely studied in isolation.

It is also recommended to stick to the daily recommended amounts of zinc, as high intakes can cause side effects and interfere with copper absorption.

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