Baking soda baths have genuine benefits for skin, backed by both long tradition and modern research. Adding a few tablespoons to a cup of baking soda to a warm bath can soften skin, relieve itching, and even help manage certain skin conditions like psoriasis. It’s not a cure-all, but for specific purposes, it’s a cheap and effective home remedy worth trying.
How Baking Soda Works on Your Skin
Baking soda (sodium bicarbonate) is mildly alkaline, with a pH between 8 and 9. Your skin’s surface, by contrast, sits around a pH of 4.5 to 5.5. When you dissolve baking soda in bathwater, it raises the pH of the water, creating a gently alkaline soak.
This shift does a few useful things. The alkaline environment helps soften rough, dry, or scaly skin by loosening dead cells on the surface. It also appears to counteract excess acidity caused by certain skin bacteria, which may reduce inflammation and irritation. Researchers have proposed that baking soda may influence how skin cells turn over and how the skin’s microbiome behaves, though the exact mechanisms are still being worked out. The practical result is that many people step out of a baking soda bath with noticeably softer, less irritated skin.
Conditions It Helps
Itching and Irritation
This is the most common reason people reach for baking soda at bath time. Whether the itch comes from dry skin, insect bites, poison ivy, or a viral rash like chickenpox, a baking soda soak can calm things down. Great Ormond Street Hospital, a leading pediatric center in London, recommends sodium bicarbonate baths specifically to soften skin, reduce itching, and support the skin’s pH balance.
Psoriasis
A clinical study tested baking soda baths on 31 patients with mild to moderate psoriasis over 21 days. Nineteen patients soaked in baking soda baths while twelve used a placebo. Nearly all the baking soda patients reported significant improvement in itchiness and irritation. The results were strong enough that patients continued using the baths on their own after the study ended. This doesn’t replace medical treatment for psoriasis, but it can be a useful add-on, especially for managing day-to-day discomfort.
Yeast Infections
A 2021 study found that baking soda helped stop the growth of Candida cells, the fungus responsible for yeast infections. A 2024 review expanded on this, suggesting baking soda has antifungal properties against many fungal strains that commonly affect skin and nails. For vulvovaginal yeast infections, a baking soda bath won’t eliminate the infection, but it can relieve the burning and itching that make daily life miserable while you treat the underlying cause.
Diaper Rash
Seattle Children’s Hospital recommends baking soda baths for babies with raw, irritated skin from diaper rash: 2 tablespoons of baking soda in a tub of warm water, soaking for 10 minutes, up to twice a day. The alkaline water helps soothe inflamed skin without harsh chemicals.
How Much to Use
The right amount depends on what you’re using the bath for. Here are the commonly recommended amounts for a full bathtub of lukewarm water:
- General skin softening: 5 tablespoons to 2 cups
- Eczema relief: 1/4 cup
- Poison ivy or poison oak: 1/2 cup
- Chickenpox: 1 cup per inch of lukewarm water
- Yeast infection symptoms: 4 to 5 tablespoons (or 1 to 2 teaspoons for a sitz bath)
- Diaper rash: 2 tablespoons only
Start at the lower end if you have sensitive skin or are trying it for the first time. The baking soda should dissolve completely before you get in. Use lukewarm water, not hot. Hot water strips natural oils from your skin and can worsen dryness or irritation.
How Long to Soak
For most purposes, 10 to 15 minutes is the sweet spot. A clinical trial studying bicarbonate baths had participants soak for at least 15 minutes daily over four weeks, with average soak times around 23 minutes. No adverse events related to skin irritation or dehydration were reported during the study. So soaking for 15 to 20 minutes is reasonable for most adults. For babies and young children, keep it closer to 10 minutes.
You can take a baking soda bath daily for short stretches if you’re managing an active flare of itching or irritation. For general maintenance, two to three times a week is plenty. Rinse off gently with clean water afterward and pat your skin dry rather than rubbing. Follow up with a moisturizer while your skin is still slightly damp to lock in hydration.
Does It Actually “Detox” You?
You’ll find claims that baking soda baths pull toxins or heavy metals out of your body. There’s no scientific evidence for this. Your liver and kidneys handle detoxification; your skin is not a significant exit route for heavy metals or metabolic waste.
What does happen is more interesting than the detox myth. Research published in Frontiers in Physiology found that sodium bicarbonate applied to the skin can be absorbed in small amounts, enough to slightly raise blood pH (about a 9% reduction in blood acidity) and reduce acid buildup in muscles by roughly 28%. This is a real physiological effect, but it’s about buffering normal muscle acidity, not “detoxing.” It may explain why some people feel their muscles relax in a baking soda bath, particularly after exercise.
Safety Considerations
Baking soda baths are safe for most people when used in the amounts described above. The main risks come from overuse or using too much. Because baking soda is alkaline, excessive concentrations can disrupt your skin’s natural acid mantle, the thin acidic layer that protects against bacteria and moisture loss. If your skin feels tight, dry, or more irritated after a baking soda bath, you’re likely using too much.
Avoid getting baking soda water in open wounds or deep cracks in the skin, as the alkalinity can sting and delay healing. For hair, baking soda is less forgiving. It opens the outer layer of the hair shaft, breaks down internal bonds, and reduces elasticity, leading to friction and breakage over time. If you’re soaking in a baking soda bath, keeping your hair out of the water is a good idea.
For babies and small children, always use the lower recommended amount (2 tablespoons) and keep soaks short. The smaller the body, the more sensitive the skin tends to be to pH changes.