What does hyaluronic acid do?

If you’ve ever noticed hyaluronic acid listed as an ingredient in a serum, eye drops or cosmetic cream, for example, you might have wondered what exactly it is and what benefits it offers. Although putting an acid near your eyes or skin might seem dangerous, hyaluronic acid is actually very safe, and it can be incredibly useful if you have dry eyes or dry skin.[1]

What is hyaluronic acid?

Hyaluronic acid is a gooey substance found naturally within the human body. It’s also known as hyaluronan or hyaluronate, and it’s found in lots of areas of the body, including the joints, the skin and the eyes. The role of hyaluronic acid is to lubricate the surfaces of your body to make movement easier and less painful. For example, by lubricating the joints, hyaluronic acid reduces joint pain and inflammation. 

At the same time, hyaluronic acid is great at storing water within the body. This is because its molecular structure contains lots of gaps where other molecules – in this case, water – can latch on. For this reason, hyaluronic acid is a common ingredient in moisturisers, creams and serums. It’s a key ingredient in dry eye treatments, as well, such as TheraTearsⓇ Dry or Tired Eye Drops, which also contain witch hazel to soothe inflammation and reduce puffiness. 

Despite its name, hyaluronic acid is one of the safest substances to use because it’s very rare to have an allergic reaction to it or suffer any side effects. This is because it’s something that is naturally produced within you, so your body is well adjusted to it and doesn’t reject the substance. It’s also fine to use if you’re pregnant or breastfeeding as it’s equally safe for babies. However, it’s best to check with your doctor or pharmacist before using products which contain hyaluronic acid, as other ingredients may cause adverse effects.[2] 

When to use hyaluronic acid in eye drops

The hydrating properties of hyaluronic acid make it an excellent option for treating dry eyes, which is why it’s often an ingredient of eye drops. You should always check the packaging and bottle to find out when to use your eye drops, whether they contain hyaluronic acid or not, but here are some rough guidelines.[3]

  • As and when your eyes feel dry, tired or itchy

Eye drops for dry eyes can be used as a spot treatment for when your symptoms flare up and get in the way of your daily activities. Remember, using eye drops usually causes a brief spell of blurred vision and discomfort, so make sure you don’t drive or use heavy machinery until your vision clears. This should only take about fifteen minutes, but if it lasts longer, you may need to speak to your doctor about choosing a different treatment.

  • First thing in the morning

If you want to avoid having to put eye drops in while you’re out and about during the day, then you may prefer to use them before you go out. Using eye drops first thing in the morning means you can factor them into your morning routine. This makes it easier for you to plan for that fifteen minutes’ buffer time to allow your vision to clear so that you’re safe to drive, ride a bike or whatever else you’re up to that day.

  • Last thing before bed

If you’d prefer not to add more steps to a busy morning routine, there is an alternative. There are plenty of overnight dry eye treatments available to help you. TheraTearsⓇ Overnight Restore Eye Drops are specially designed to rejuvenate your eyes while you sleep. Our preservative-free formula is rich in hyaluronic acid to keep your eyes hydrated and refreshed.


[1] Hynnekleiv, Leif et al. “Hyaluronic acid in the treatment of dry eye disease.” Acta ophthalmologica vol. 100,8 (2022): 844-860. doi:10.1111/aos.15159 Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9790727/

[2] Papakonstantinou, Eleni et al. “Hyaluronic acid: A key molecule in skin aging.” Dermato-endocrinology vol. 4,3 (2012): 253-8. doi:10.4161/derm.21923 Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583886/

[3] https://www.nhs.uk/conditions/dry-eyes/



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Dr Simon Cooper

Dr Simon Cooper

Working with the TheraTears marketing team, as well as with a number of other Prestige Brands, Dr Simon Cooper brings extensive knowledge and experience in a number of key areas. With a PhD in biochemistry from the University of Cambridge, and before that a BA in biological sciences from the University of Oxford, he brings immense technical expertise.

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