Could Your Medication Make You More Sensitive to the Sun?
Sun-sensitive medicines are more common than many people realise. Some UK medicines, including doxycycline, lymecycline, ciprofloxacin, naproxen, amiodarone and certain water tablets, can make your skin react more strongly to sunlight.
For some people, this may mean burning more quickly than usual. For others, it can mean redness, itching, rashes, blistering or darker patches of pigmentation after time outdoors.
This does not mean you need to avoid sunshine completely. Sunlight supports mood, sleep, vitamin D and outdoor activity. But if you take a medicine that increases sun sensitivity, it is worth knowing how to protect your skin properly.
What Are Sun-Sensitive Medicines?
Sun-sensitive medicines are medicines that can make the skin more reactive to ultraviolet light, also known as UV light.
This reaction is called photosensitivity. It can happen when a medicine in the body or skin absorbs UV light and triggers an exaggerated skin response.
There are two main types:
- Phototoxic reactions — more common and often look like severe sunburn.
- Photoallergic reactions — less common and may look more like an itchy eczema-type rash.
Photosensitivity can happen in the UK as well as abroad. You do not need to be on a beach in Spain to burn. Gardening, walking, golf, festivals, sitting outside a café, or driving with sunlight through a window may be enough for some people.
Doxycycline and Sun Exposure
Doxycycline is one of the best-known examples of a sun-sensitive medicine.
It may be prescribed for:
- Acne
- Rosacea
- Chest infections
- Sinusitis
- Lyme disease
- Malaria prevention
Many people take doxycycline without any skin problems. However, some people can develop an unexpectedly strong sunburn reaction after relatively modest sun exposure.
This can be especially frustrating because people often say:
“I used the same sun cream I always use — but I still burned.”
The issue is not that the sun cream has suddenly stopped working. It may be that the medicine has changed how the skin reacts to sunlight.
Other UK Medicines That May Increase Sun Sensitivity
Doxycycline is not the only medicine linked with photosensitivity. The risk varies between medicines and between individuals, but examples include:
Antibiotics
- Doxycycline
- Lymecycline
- Tetracycline
- Ciprofloxacin
- Co-trimoxazole
Acne and Skin Medicines
- Isotretinoin, sometimes known by the brand name Roaccutane
- Doxycycline
- Lymecycline
- Tretinoin creams
- Adapalene creams or gels
Pain and Anti-Inflammatory Medicines
- Naproxen
- Piroxicam
- Ibuprofen, less commonly but still worth being aware of
Water Tablets and Blood Pressure Medicines
- Bendroflumethiazide
- Hydrochlorothiazide
- Furosemide
- Indapamide
Heart Medicines
- Amiodarone
Mental Health and Nerve Pain Medicines
- Amitriptyline
- Nortriptyline
- Chlorpromazine
- Some SSRIs, although this is less common
Antihistamines and Travel Sickness Medicines
- Promethazine
- Cyclizine
This list is not exhaustive. If you are unsure whether your medicine may increase sun sensitivity, ask a pharmacist or check the patient information leaflet supplied with your medicine.
What Does Medicine-Related Sun Sensitivity Look Like?
Medication sun sensitivity can look different from person to person.
Possible symptoms include:
- Burning more quickly than usual
- Redness after short sun exposure
- Itching or stinging skin
- A blotchy rash on sun-exposed areas
- Swelling
- Blistering
- Peeling
- Darker patches of pigmentation after healing
It often affects areas exposed to light, such as the face, neck, forearms, hands, lower legs and the tops of the feet.
One clue is that covered areas may be unaffected, while exposed areas look red, sore or rash-like.
A Summer Holiday That Goes Wrong
Every summer, pharmacists hear some version of the same story.
Someone starts doxycycline for acne, rosacea or an infection. A week later, they go on holiday, play golf, spend time in the garden, or sit outside in the sun.
They use the same SPF they normally use.
By evening, they are far more burned than expected.
This is why sun-sensitive medicines matter. They can turn ordinary sun exposure into a much stronger skin reaction.
Does Sunscreen Prevent Photosensitivity?
Sunscreen helps enormously, but it is not a complete guarantee.
If you are taking a medicine that can increase sun sensitivity, it is best to combine several approaches:
- Use a broad-spectrum sunscreen with SPF 30 or higher
- Choose good UVA protection
- Apply sunscreen generously
- Reapply at least every two hours
- Reapply after swimming or sweating
- Wear a wide-brimmed hat
- Wear sunglasses with UV protection
- Cover shoulders, chest and arms where possible
- Seek shade during the strongest sun
- Avoid sunbeds
Many reactions happen because people rely on one thin morning layer of sun cream, then spend hours outdoors.
Sun-Sensitive Medicines and Skin of Colour
People with darker skin tones may be less likely to burn visibly, but photosensitivity can still happen.
Redness may be harder to see on brown or black skin. Symptoms may show more as tenderness, itching, swelling, a change in skin texture, or darker pigmentation afterwards.
Anyone taking a sun-sensitive medicine should take sun protection seriously, whatever their skin tone.
Heat, Hydration and Sun-Sensitive Medicines
Sun exposure often happens alongside heat. That combination matters.
Hot weather can increase sweating, dehydration, dizziness and fatigue. Some medicines can also affect hydration, blood pressure or the way the body copes with heat.
That means summer health is not only about avoiding sunburn. It is also about hydration, medication safety, sleep, skin protection and knowing when to slow down.
Related reading:
Sun exposure is only one part of staying healthy during summer. Hot weather can also affect hydration, sleep, blood pressure and the way some medicines work in the body. You may also find our articles on summer medication safety and healthy fluid habits helpful.
Should You Stop Taking Your Medicine?
No. Do not stop prescribed medication simply because it may increase sun sensitivity.
For most people, the benefits of treatment far outweigh the risk of photosensitivity, particularly when sensible sun protection measures are used.
Seek advice from a pharmacist, GP or prescriber if:
- You develop severe sunburn after limited sun exposure.
- Your skin blisters, swells or becomes very painful.
- You develop a widespread rash.
- You feel generally unwell after being in the sun.
- You are planning a sunny holiday and are concerned about your medication.
In many cases, simple precautions are all that is needed. A pharmacist, GP or prescriber can advise whether extra sun protection measures are sufficient or whether an alternative treatment may be more suitable.
Practical Sun Safety Tips While Taking Medication
- Check your patient information leaflet for photosensitivity warnings.
- Use SPF 30 or higher with good UVA protection.
- Apply sunscreen generously and reapply regularly, especially after swimming or sweating.
- Wear a hat, sunglasses and protective clothing when practical.
- Avoid sunbeds completely.
- Take extra care near water, sand and other reflective surfaces.
- Remember that UV exposure can still be significant on cloudy days.
- Store medicines away from excessive heat and direct sunlight.
- Stay well hydrated during warm weather.
Frequently Asked Questions
What sun cream should I use while taking co-trimoxazole?
If you are taking co-trimoxazole or another medicine that can increase sun sensitivity, choose a broad-spectrum sunscreen with SPF 50+ and good UVA protection. Look for the UVA circle logo or a 4- or 5-star UVA rating.
Apply sunscreen generously before going outdoors and reapply regularly, especially after swimming or sweating. Sunscreen works best when combined with shade, protective clothing, sunglasses and avoiding prolonged exposure during the strongest part of the day.
How long after finishing co-trimoxazole should I be careful in the sun?
Photosensitivity does not necessarily disappear the moment you take your last tablet. As a general guide, it is sensible to continue taking extra care in the sun for at least 48 hours after your final dose, allowing time for the medicine to leave your body.
If you developed a significant sun reaction while taking co-trimoxazole, continue to protect your skin until it has fully settled and seek advice if symptoms persist or you are unsure.
Questions We’ve Been Asked
Many of our health articles are inspired by real questions people ask in the pharmacy, online or through our website.
This article was updated after someone asked what sun lotion to use while taking co-trimoxazole, and how long after the last tablet they should continue being careful in the sun.
If one person is wondering, there is a good chance others are too. That is why we try to turn common questions into practical, easy-to-understand advice.
The Sun Is Not the Enemy
It is easy for health advice to make the sun sound like a villain.
But sunshine also plays an important role in wellbeing. It helps support circadian rhythm, mood, outdoor movement, social connection and vitamin D production.
The goal is not to hide indoors all summer.
The goal is to understand your personal risk and adapt sensibly — especially if you are taking sun-sensitive medicines.
When to Ask a Pharmacist
If you are starting a new medicine and planning a holiday, gardening, walking, golf, cycling, outdoor work or a festival, it is worth asking:
“Could this medicine make me more sensitive to the sun?”
You can also read this BBC report on medicine and sun reactions for more background.
At The Health Dispensary, we can briefly advise customers with medicine-related queries and help you choose suitable sun protection and hydration support where appropriate.
Final Thoughts
Sun-sensitive medicines are not rare, and doxycycline is only one example.
Many common UK medicines can make the skin more reactive to sunlight. For most people, this simply means being more careful with sunscreen, clothing, shade and hydration.
Summer should still be enjoyed. But if your medicine changes how your skin responds to the sun, a little extra knowledge can prevent a painful burn, a ruined holiday and unnecessary worry.
Check your leaflet. Ask your pharmacist. Respect the sun.
That is whole health too.
Written by Ali Sparkes, Independent Prescribing Pharmacist & Founder of The Health Dispensary
