When to replace these eight common household items

Unlike food, household items like pillows, mascara, and toothbrushes don't typically come with an expiration date. Here's a guide to how often you should replace some of the most commonly overused items, and some of them may surprise you.

I think it's time for an intervention. Put down the fancy mascara your aunt got you for Christmas 2007. Take your head off the pillow you've been sleeping with since childhood. I know you love these things, but your relationship with them is no longer healthy. It's time to let go. 

We're all guilty of holding onto stuff like this for way longer than we should. And it's easy to understand why! Unlike food, household items don't typically come with an expiration date, so it can be difficult to know just how often to replace these things. We put together a guide for how often you should replace some of the most commonly overused items, and some of them may surprise you.

Toothbrushes: every 3-4 months.

You might think this recommendation is based on the fact that old toothbrushes are germy, but according to the American Dental Association, this is more about the state of your bristles than anything else. Your toothbrush's cleaning powers become significantly less effective as the bristles become worn down and flat, so brushing with an old toothbrush means a lot more plaque will be left on your teeth and gums.

If you want to take the hassle out of running to the drug store every time you get sick or your bristles go flat, check out this deal on a 12 pack of Oral-B toothbrushes from iTechdeals.com. Right now they're on sale for $11 (down from $29.99), so you'll get 'em at less than $1/toothbrush and have brushes coming out of your ears for years to come.

Changing your oil: BEFORE the oil change light comes on.

Mechanics used to recommend an oil change every 3,000 miles, but advances in engineering have caused that number to skyrocket in the past few years. The problem is, the new standards are different for every car. Luckily, you don't have to guess what the right number is for your car, because it's listed in the owner's manual. So look that up, keep it in mind, and switch out your oil well before you reach it. According to CARFAX, one of the worst things you can do is rely on that low oil light to remind you to make the change:

"You shouldn’t see that light unless your oil level is low. So you don’t want to see it. Whatever amount of oil you do have left almost certainly has lost its ability to function properly."

Pillows: every 1-3 years (and/or wash them regularly).

This is one you might not think about, but if you want to freak yourself out, do a quick Google search for "dust mites in pillows," I'll wait. Creepy, right?

I've personally had my pillows for about three years, and when I read a recent Daily Mail article that claimed I needed to replace my pillows every six months I was more than a little grossed out. However, the Daily Mail was probably overreacting, because the author of that article doesn't seem to realize that washing machines are a thing. If you wash your pillows regularly (every 3-6 months), you don't need to buy a brand new set every year. According to Robert Oxeman, the director of the Sleep to Live Institute who was asked about this issue in a September 2015 Huffington Post article, "Down-alternative pillows can go in the washing machine, while down feather pillows should be dry cleaned. Thirty minutes on low in the dryer can help clear out some of the clutter from your pillows between cleanings."

If your pillows have reached the point of no return, you can pick up new ones on the cheap with this Bed Bath & Beyond 60 percent off pillow sale.

Makeup: depends on the product.

I'm a makeup hoarder so I wasn't pleased to learn that half my collection was overdue for a swap out. Here's how often to replace the most common items in your makeup bag:

• Mascara -- Replace every 3 months.
• Eyeliner -- Replace every 2 years.
• Foundation -- Replace every 6 months to 1 year.
• Powders/Blush -- Replace every 1 to 2 years.
• Lipstick -- Replace every two years.

We've got some great deals to help you refresh your makeup bag, including this Pur Minerals build your own custom five-piece makeup kit, which includes a pressed mineral powder foundation, an eye shadow trio, a chisel brush, an eyeliner pencil and a lip color for just $29. Check out all our deals on makeup here.

Bras: every 1-2 years.

This is all dependent on how well you take care of them, but in general you should replace a bra if it's lost its shape, elasticity, gotten too big or small, or has a few pesky underwires poking out of it--I think we all know that pain. However if you hand wash your bras, keep them out of the dryer, store them carefully and have a large collection that you rotate in and out, you can extend their lifetimes quite a bit.

Bras are expensive, which is why many women wear them into the ground. Maidenform currently has a 3 for $17 deal going on that can help you beef up your bra collection without breaking the bank.

Running Shoes: every 300-500 miles.

In general, running is great for your health. But running with worn down shoes can cause arch issues and increase your risk of injury.

If you use a fitness tracking app to route your runs, it should be easy to figure out when you've hit 300 miles. Otherwise, make sure to regularly inspect your shoes for signs of wear and tear. If the soles are worn down beyond recognition, and the midsole feels tough instead of springy when you push your thumb into it, it's probably time for a new pair.

If you need a new pair, Brad's Deals has you covered. Seriously, check out our very wide selection of deals on running shoes, and pamper those precious feet!

Spices: every 1-4 years.

Spices can sit in the back of your cabinet for years without being so much as looked at, but while you might think they're everlasting, they do need to be replaced from time to time. According to a blog post on the aptly-named Spices Inc, if you store spices correctly (in airtight containers in a dark, cool place), this is how long you should expect them to last:

• Whole spices and dried herbs, leaves and flowers -- 1 -to 2 years.
• Seeds -- 2 to 3 years.
• Whole roots  -- 3 years.
• Ground spices and herb leaves -- 1 year.
• Ground roots -- 2 years.

Smoke Alarm Batteries: every year.

This one hits home for me, as my cousin and her new husband lost their house and all their belongings (including ALL their wedding presents) to a huge house fire last weekend. Their smoke alarm didn't go off, because their landlord had neglected to replace the batteries for years, and if they didn't wake up to the sound of windows breaking, they would have probably lost their lives as a result of this negligence.

If you rent, it's your landlord's responsibility to make sure your smoke detectors are in good, working order. But even so, you should make it a point to check your alarm's batteries and test them every few months just in case. It might be annoying, but your life is worth it. Seriously.

What else do you think is important to replace regularly? Let us know in the comments below!