Medically reviewed by Mary Lucas, RN
Written by Our Editorial Team
Last updated 5/15/2022
If you have female pattern hair loss, hormonal acne or another condition caused by high levels of androgen hormones, your healthcare provider may prescribe the medication spironolactone to help you control your symptoms.
What is spironolactone 25mg? Spironolactone is a prescription medication that’s available in a range of dosage forms. When spironolactone comes in tablet form, 25mg is the lowest dosage that’s available.
If you’re prescribed spironolactone, your healthcare provider may recommend taking 25mg per day, or prescribe you a higher dose.
Below, we’ve explained what spironolactone is, as well as how it works to treat common issues such as hair loss and acne.
We’ve also discussed how you should take spironolactone, as well as the maximum dosage of spironolactone for hair loss, acne breakouts and other conditions.
Spironolactone is a prescription medication that’s approved by the FDA to treat hypertension (high blood pressure), congestive heart failure, hyperaldosteronism (high levels of a hormone called aldosterone), and edema (fluid retention) caused by liver or kidney disease.
Currently, spironolactone is sold as Aldactone®. It’s also available under several brand names as a generic drug.
Spironolactone belongs to a class of medications called aldosterone receptor antagonists. It works by preventing the activity of aldosterone, a hormone that can cause your body to retain water.
By reducing the effects of aldosterone, spironolactone stimulates the kidneys to release extra water and sodium from your body, all while sparing the mineral potassium.
Because it promotes fluid loss without reducing potassium levels, spironolactone is referred to as a potassium-sparing diuretic, or “water pill.”
Like many other prescription medications, spironolactone is often used off-label to treat certain conditions other than its FDA-approved indications.
For example, spironolactone is often used as an off-label medication for androgenetic alopecia (the clinical term for female pattern hair loss), and as one of several medications for managing hormonal acne breakouts.
As a treatment for hair loss and acne, spironolactone works by reducing the effects of androgen hormones, or male sex hormones, in your body.
Some androgens, such as dihydrotestosterone (DHT), can attach to receptors in your scalp and cause your hair follicles to gradually shrink and stop producing new hairs. Blocking the effects of these androgens may help to treat female pattern hair loss.
Many of these androgen hormones are also involved in acne, such as testosterone, which plays a major role in stimulating your sebaceous glands and giving you oily skin.
By reducing androgen levels and stopping these hormones from exerting their full effects in your body, spironolactone can help to slow down or stop hormonal hair loss and clear your skin if you often develop hormonal acne breakouts.
Spironolactone is available as a tablet and as a suspension, or liquid, both of which are taken by mouth.
So, what is spironolactone 25mg? Spironolactone tablets are available in several strengths, and 25mg is the lowest-strength tablet that’s currently available. Other spironolactone tablets come in 50mg and 100mg doses.
If you’re prescribed spironolactone and don’t know the dosage of your tablets, you can find it by checking the packaging that comes with your medication.
Because female pattern hair loss is an off-label indication for spironolactone, there’s no precise, agreed-upon dosage. However, most healthcare providers prescribe spironolactone for hair loss at a dosage of 100mg to 200mg per day.
If you’re prescribed spironolactone for hair loss, your healthcare provider will usually instruct you to take your medication in a single dose, either in the morning or evening.
This means using one 100mg tablet, two 50mg tablets or four 25mg tablets. Make sure to check the dosage of your spironolactone tablets before you take them, as it’s easy to accidentally take an excessive dose.
Spironolactone can be used with or without food. It’s important to be consistent and either take your daily dose of spironolactone with food or without food every time, as your food intake could affect your body’s ability to absorb this medication.
For more information, you can read our Spironolactone Dosage Guide.
If you’re prescribed spironolactone, it’s important to follow the dosage instructions provided by your healthcare provider.
As a treatment for female pattern hair loss, spironolactone is usually prescribed at a dosage of 100mg to 200mg per day.
To treat inflammatory acne in women, spironolactone is prescribed at a dosage of 25mg to 200mg per day. If you’re prescribed spironolactone to treat acne, your healthcare provider will usually suggest starting at a low dose, then gradually increasing your dose over time as required.
Spironolactone may be prescribed at different dosages to treat other conditions:
To treat congestive heart failure, spironolactone is usually taken at a dosage of 25mg one time per day.
To treat hypertension (high blood pressure), spironolactone is usually prescribed at a dosage of 25mg to 100mg per day, taken in either single or divided doses.
To treat edema (fluid retention), spironolactone is usually taken at a dosage of 100mg per day in single or divided doses.
To treat primary hyperaldosteronism (high aldosterone production), spironolactone is usually given at the lowest effective dosage, or at a dosage of 100mg to 400mg per day prior to surgery.
Make sure to only take the dosage that’s prescribed by your healthcare provider. If you miss a dose of spironolactone, take it as soon as you remember. However, you should not take more than one dose of spironolactone at a time to make up for a missed dose.
Spironolactone is a safe and effective medication when it’s used as prescribed. However, it can potentially cause adverse effects and drug reactions, including some that may affect your health and wellbeing.
Common side effects of spironolactone include:
Hyperkalemia (high levels of potassium in the blood)
Hyponatremia (low levels of sodium in the blood)
Stomach upset, nausea, diarrhea and/or vomiting
Reduced appetite and eating disorders such as anorexia
Headaches, drowsiness, confusion and changes in motor control
Muscle pain, cramps and/or weakness
Spironolactone may affect your menstrual period. Some women experience breast discomfort, tenderness and breast pain while using spironolactone.
It’s also important to monitor your blood pressure when you start using Spironolactone, as it may cause your blood pressure to drop, making you feel lightheaded or dizzy. Let your healthcare provider immediately if you experience this or other side effects.
Because of its effects on potassium, spironolactone should not be used with dietary potassium supplements or potassium-containing salt substitutes. Potassium-rich fruits, such as bananas, raisins, prunes and orange juice, may increase your risk of side effects from spironolactone.
In certain cases, spironolactone may cause more serious or persistent side effects. Our guide to spironolactone side effects provides further information about potential adverse events and drug interactions to be aware of before using spironolactone.
Spironolactone is one of several medications for female pattern hair loss, acne breakouts and other medical conditions associated with high androgen levels. It’s available in several dosage forms, including 25mg, 50mg and 100mg tablets.
If you’re prescribed spironolactone, it’s important to take it as the dosage recommended by your healthcare provider. For more information on getting prescribed, you can read our guide on how much spironolactone costs.
Interested in using spironolactone to prevent shedding and improve your hair growth? We offer spironolactone for female hair loss online as part of our range of hair loss treatments, following a consultation with a healthcare provider who will determine if a prescription is appropriate.
We also offer other evidence-based medications for treating female pattern hair loss, including minoxidil solution and minoxidil and finasteride spray.
Finally, you can learn more about how spironolactone works, its potential benefits and more in our detailed guide to spironolactone.