A handful of inexpensive pantry items can turn a plain bath into genuine itch relief. Colloidal oatmeal, baking soda, diluted bleach, magnesium-rich salts, and apple cider vinegar all have evidence behind them, though each works differently and suits different situations. What matters just as much as what you add is how you bathe: the water temperature, how long you soak, and what you do in the minutes right after you get out.
Colloidal Oatmeal
Colloidal oatmeal is finely ground oat powder that dissolves in water and coats the skin with a thin protective film. It’s the most well-studied bath additive for itching, and it works through specific compounds called avenanthramides. These block the release of histamine and inflammatory signaling molecules in the skin, which are the same chemicals responsible for the itch-scratch cycle in conditions like eczema, contact dermatitis, and dry winter skin.
You can buy colloidal oatmeal packets at most drugstores (Aveeno is the most common brand), or make your own by grinding plain, unflavored oats in a blender until the powder turns silky and dissolves completely in water. Use about one cup per full bath. The water should look milky. Soak for 10 to 15 minutes, then pat dry gently rather than rubbing.
Baking Soda
Baking soda is a mild alkaline powder that can calm surface-level itching and help balance skin pH when irritation has made the skin too acidic or reactive. The National Eczema Association recommends adding 1/4 cup of baking soda to a lukewarm bath. It dissolves easily and won’t leave residue if you rinse lightly afterward.
Baking soda works best for generalized, mild itching rather than intense flare-ups. It’s particularly useful for itch caused by bug bites, mild sunburn, or heat rash. Avoid it if you have large open wounds or cracked, bleeding skin, as it can sting and delay healing.
Magnesium-Rich Salts
Epsom salt (magnesium sulfate) and Dead Sea salt both deliver magnesium through the bathwater. A study on people with atopic dry skin found that bathing in a magnesium-rich Dead Sea salt solution significantly reduced skin roughness and redness, improved the skin’s moisture barrier, and increased hydration in the outermost layer of skin. Magnesium helps skin cells retain water and supports the repair of the skin barrier, which is the root problem behind most chronic itching.
Add about two cups of Epsom salt or Dead Sea salt to a full bath. One caution: soaking too long in salt water can irritate skin rather than help it, so keep these baths to 10 to 15 minutes. If your skin is cracked or raw, salt baths will likely sting and are better saved for intact skin that’s dry and itchy rather than actively broken down.
Diluted Bleach
A bleach bath sounds aggressive, but at the right dilution it’s roughly as strong as a swimming pool and is a well-established treatment for eczema-related itching. The purpose is to reduce bacteria on the skin, particularly the type that colonizes eczema-prone skin and drives inflammation and itch.
The Mayo Clinic recommends 1/4 cup of regular household bleach (not concentrated or scented) in a half-full bathtub, or 1/2 cup in a completely full tub. If your bleach has a higher sodium hypochlorite concentration (closer to 8% rather than 6%), use a bit less. Soak from the neck down for 5 to 10 minutes, then rinse with fresh water and moisturize immediately. Bleach baths are typically done two to three times per week, not daily. Skip them entirely if you have large open wounds or cuts.
Apple Cider Vinegar
Apple cider vinegar is sometimes recommended to restore the skin’s natural acidity. Healthy skin sits at a slightly acidic pH, which keeps harmful bacteria in check. In conditions like eczema, the skin becomes more alkaline, allowing bacteria to thrive and trigger more itching. The idea behind an ACV bath is to nudge that pH back toward its natural acidic range.
The evidence here is more limited. One clinical study that tested apple cider vinegar soaks on eczema patients found that it did not significantly change the skin’s bacterial balance, though some people report subjective itch relief. If you want to try it, dilute it heavily: about two cups of apple cider vinegar in a full bathtub. Never apply undiluted vinegar to irritated skin, as it can cause chemical burns. Discontinue if you notice stinging or increased redness.
Water Temperature Matters More Than You Think
Hot water feels soothing in the moment, but it strips the skin’s natural oils and triggers histamine release, which makes itching worse after you get out. Dermatologists consistently recommend lukewarm water for anyone dealing with itchy skin. If the water feels warm but not hot to the inside of your wrist, that’s about right.
This is especially important in winter, when people tend to take hotter baths to warm up. The temporary relief gives way to a rebound of dryness and itching within an hour, creating a cycle that gets worse over time.
Keep Soaks Short
Longer is not better. The American Academy of Dermatology recommends keeping showers to 5 to 10 minutes, and therapeutic baths should generally stay under 15 minutes. Extended soaking dissolves the lipids that hold your skin barrier together, leaving skin more porous and prone to moisture loss once you towel off. If you’re adding something to the water for itch relief, 10 to 15 minutes gives the active ingredients enough contact time without degrading the barrier you’re trying to protect.
What to Do Immediately After
The minutes right after your bath are arguably more important than what you put in the water. When you step out, your skin is temporarily saturated with moisture, but that moisture evaporates quickly and can leave skin drier than before unless you seal it in.
Pat your skin until it’s damp but not dripping, then apply a thick moisturizer or ointment while the skin is still slightly wet. This technique, sometimes called “soak and smear,” traps water in the outer layer of skin and prevents the tight, itchy feeling that often follows a bath. Ointments and creams work better than lotions for this purpose because they contain more oil and less water. Petroleum jelly, ceramide-based creams, or any fragrance-free body cream will work. The key is speed: aim to get the moisturizer on within a few minutes of stepping out.
When to Skip the Bath
Therapeutic baths are not always a good idea. If your skin has large open wounds, widespread cracking, or areas that are actively weeping fluid, soaking can introduce bacteria and worsen the damage. This applies to all bath additives, including gentle ones like oatmeal and baking soda. In those cases, spot-cleaning with a damp cloth and applying moisturizer to intact areas is safer until the skin has healed enough to tolerate submersion.
If your itching is accompanied by fever, rapidly spreading redness, or swelling that feels warm to the touch, those are signs of infection rather than simple dryness, and a bath additive won’t address the underlying problem.