It depends on what you mean by “two at the same time.” If your prescription says to take two capsules per dose, then yes, that’s exactly what you should do. Many prescriptions call for 300mg of clindamycin, and pharmacies often dispense this as two 150mg capsules taken together. But if you’re thinking about doubling your prescribed dose, whether to catch up on a missed pill or to try to fight an infection faster, the answer is no.
Why Two Capsules Per Dose Can Be Normal
Clindamycin capsules come in two strengths: 150mg and 300mg. For serious infections, the standard adult dose ranges from 150mg to 300mg taken every six hours. For more severe infections, doses go up to 450mg every six hours. So if your doctor prescribed 300mg and your pharmacy filled it with 150mg capsules, taking two at once is your correct dose. Check your prescription label: it will tell you exactly how many capsules to take and how often.
If your label says “take 2 capsules by mouth every 6 hours,” you’re meant to swallow both together. That’s not doubling up. That’s one dose.
Don’t Double a Dose You Missed
If you forgot a dose and are thinking about taking two doses’ worth to make up for it, don’t. Mayo Clinic guidance is clear: if you miss a dose, take it as soon as you remember. But if it’s close to the time for your next scheduled dose, skip the missed one entirely and get back on your regular schedule. Do not double doses.
The reason this matters is that clindamycin works by maintaining a steady level in your bloodstream over time. Taking a double dose doesn’t make it twice as effective. It just spikes the concentration in your system and increases your risk of side effects without meaningfully helping the infection clear faster.
What Happens If You Take Too Much
The most common problem with higher-than-prescribed doses of clindamycin is gastrointestinal distress. Clindamycin works by killing bacteria, but it doesn’t only target the infection. It also wipes out healthy bacteria in your gut, which can cause nausea, vomiting, and diarrhea. These effects get worse at higher doses.
The more serious concern is a condition called pseudomembranous colitis, a severe inflammation of the colon caused by a bacterium called C. difficile. Clindamycin is already associated with a roughly three-fold increased risk of C. difficile infection compared to many other antibiotics, because of how aggressively it disrupts gut bacteria. Taking more than prescribed pushes that risk higher.
In rare cases, clindamycin toxicity can cause heart rhythm problems. This is uncommon at oral doses, but it’s another reason not to take more than what’s on your label.
How to Take Clindamycin Properly
However many capsules make up your prescribed dose, swallow them whole with a full glass of water. This isn’t optional advice. Clindamycin can irritate your esophagus and even cause esophageal ulcers if the capsule gets stuck or dissolves before it reaches your stomach. Drink plenty of water and stay upright for at least 30 minutes after taking it. Don’t take it right before lying down for bed.
Take your doses at evenly spaced intervals. If your prescription says every six hours, try to stick close to that schedule. Consistent spacing keeps the drug at effective levels in your blood and gives the antibiotic the best chance of clearing the infection completely. Skipping doses or taking them irregularly can allow bacteria to survive and potentially develop resistance.
If You Already Took Extra
If you accidentally took a double dose once, you’ll likely be fine, though you may experience more stomach upset than usual. Watch for persistent diarrhea, especially watery or bloody stool, which could signal C. difficile or colitis. Severe vomiting or diarrhea can also throw off your electrolyte balance, so stay hydrated. If symptoms are mild, resume your normal dosing schedule at the next scheduled time. If you’re experiencing significant GI symptoms or anything feels off, call your pharmacist or prescriber for guidance on when to take your next dose.