9 best drain unblockers to unclog your sinks and baths

For a little more than £2, this do-it-all supermarket offering was the best drain unblocker on test. Designed for use in bathrooms and kitchens, it’s fast-acting (it unclogs simple build-ups in just 15 minutes) and fairly gentle on the nose. It’s become a must-have in my household cleaning cupboard.

My bathroom sink had been draining painfully slowly, so I poured this thick gel down the plughole. After leaving it for 15 minutes, I could see the formula bubbling away – a sign it was working. The thick gel texture is designed to stick to blockages, helping to break down stubborn grime effectively. I found it cuts through kitchen sink grease just as well as it does through hair clogs in bathroom pipes. There was a slight bleachy smell during use, but it wasn’t overwhelming, and it disappeared after rinsing. For the price, this is a solid all-rounder that works fast.

This is the best drain unblocker for bathroom sinks and showers, which are notorious for slow drainage, thanks to hair, soap scum, and shaving foam clogging up the pipes. I put a generous-sized clump of hair from a hairbrush into the sink before testing this unblocker gel and saw water starting to pool in the basin. However, within 30 minutes, this formula had worked its magic, and water was flowing freely down the drain once again. Unlike some drain cleaners, this product didn’t produce excessive foaming, but it was clearly effective.

While a 1l bottle of this solution is pricier than supermarket alternatives, it contains three applications – I only needed to use 300ml per treatment. As it works so fast, it’s well worth the investment for tackling tough bathroom clogs. I was also very impressed by the fact it has hardly any odour.

The best drain unblocker for unblocking hair build-up hails from Ecozone. If you wash your hair a few times a week at home, some of it will inevitably end up in the drain. Over time, this gathers up into a ball, making it impossible for water to pass. I put Ecozone to the test in a shower used by three long-haired girls and was stunned by how well it worked.

Ecozone relies on plant-based enzymes that effectively eat their way through blockages such as hair. Unlike chemical cleaners, which attack everything in their path, enzyme-based cleaners only break down organic matter, rather than the lining of pipes. I also liked that it comes in a large 1l bottle, which is enough for multiple treatments. However, it’s pretty slow. It needs to be left overnight, but the speed of the water flow the following day was worth the wait.

The best sink and drain unblocker for kitchens is yet another supermarket offering. Though it looks nearly identical to the Sainsbury’s unblocker, the two products have slightly different ingredients. Waitrose’s own-brand drain unblocker isn’t as strong as other chemical unblockers I tested. According to the ingredients list, it contains bleach and caustic soda, but at lower concentrations. This makes it more pleasant to use in smaller bathrooms and those without windows.

The lower concentration of chemicals doesn’t seem to affect performance at all, though. It produced a satisfying gurgle and bubble from our drain, and I found it had almost cleared the pipes after one hour. When I left it overnight, it made all the clogs vanish completely.

Short on time and looking for the best fast-acting drain unblocker? Mr Muscle impressed on test. Kitchen sinks deal with some of the worst blockages – grease, food particles and washing-up liquid residue all combine to slow drainage over time. However, Mr Muscle’s potent mix of caustic soda and bleach helps to dissolve fat, oils, and organic matter fast. I tested it on a sink that had been draining sluggishly, and, within 15 minutes, bubbling foam indicated it was getting to work. After flushing it with hot water, the drain was completely clear.

The fast-acting chemical reaction makes this one stand out. It doesn’t just coat the blockage, it aggressively breaks it down. That does produce a strong smell, though, so, it’s best to ventilate the room when using this one. While it’s fantastic for kitchen sinks, it might be too harsh for delicate plumbing or eco-conscious households.

Eschewing harsh chemicals, Delphis’s drain-cleaning tablets were the best eco-friendly drain unblocker on test. Instead of relying on caustic agents, they use enzymes to break down build-ups over time. It’s recommended to put one tablet in the sink, rinse it, and then see if you need any extras. I needed two doses to see an effect, so I think they work best as a preventative measure rather than a quick fix.

Because they use enzymes, these tablets don’t produce strong fumes. They’re ideal for homes with children, pets and anyone sensitive to chemicals. It’s usually on sale for £10, so each application is £1, which is among the lowest cost-per use of all the drain unblockers I tested. However, if you have a severe blockage, you may need a stronger solution first.

If you’re looking for the best fragrance-free drain cleaner that’s gentle on your pipes but tough on blockages, this one is a great choice. Unlike chemical-heavy alternatives, it relies on plant-based enzymes to break down organic matter, so it’s a good option if you dislike strong smells. After pouring this into my bath and leaving it overnight, I flushed it with hot water in the morning and noticed a clear improvement in water flow.

I love that this formula is biodegradable and free from harsh fumes. This makes it a perfect choice for homes with sensitive plumbing. However, it is a thinner consistency than other unblockers, and it works gradually, so, it’s not the best pick for emergency unblocking – especially if you’re dealing with stubborn hair clogs or grease-heavy kitchen sinks.

I highly doubt that Buster’s bathroom plug unblocker will let you down if you’re looking for the best drain unblocker for showers. Kitchen and bathroom sinks often face different types of blockages, so this product is specifically designed to tackle common bathroom clogs. I’m talking hair, soap scum, shower oils, shaving foam and toothpaste residue. I was sceptical whether or not the small bottle of 300ml could make much of a difference, but after leaving it to do its thing for less than half an hour, then rinsing with hot water, my water flowed freely again, with no need for a second treatment.

Buster offers a money-back guarantee, providing reassurance that it will get the job done. I like this confidence, and the plug unblocker did work wonders during testing. However, the strong chemical formula has a noticeable smell – you’ll want to open the windows while using this product.

If you want to prevent problems from occurring in the first place, this is my pick of the best drain unblocker for preventing blockages. At £2.16 for a bottle that contains one treatment, it’s one of the most budget-friendly options available, making it ideal for regular maintenance. I also liked that it’s versatile enough to use in both kitchen and bathroom sinks.

However, it’s not the best drain cleaner I tested. I used this in a slow-draining bath that had hair and soap scum build-up, and while it didn’t clear the blockage immediately, it helped significantly reduce the drain’s sluggishness. With a couple more treatments, it would have cleared it all. As an Amazon product, it’s available on subscription, which is ideal if you plan to use a drain cleaner regularly as a preventative measure.