These drugs are used to treat breast cancer in postmenopausal women. They work by blocking the conversion of androgens into estrogen in the body. Why does this matter for your bones? Because estrogen is one of the greatest protectors of the female bone. It’s what keeps the demolition team, the osteoclasts, in check. When you block estrogen with these medications, it’s like taking the brakes off a car on a steep hill. Bone demolition accelerates, even faster than natural menopause would cause.
But now, pay close attention to what I’m about to say. Do not stop this medicine. This medicine is protecting you from cancer. We can monitor bones, we can replenish them, we can take care of them, but cancer sometimes doesn’t give a second chance. Now you understand why your oncologist told you to take that calcium, why they ordered a bone density scan every year, why they might have prescribed that anti-osteoporosis injection you didn’t understand the purpose of. They already knew. Now you know too. If you take anastrozole or letrozole, your mission is simple: at your next appointment, ask your oncologist, “Doctor, how are my bones? Are we monitoring them properly?”
4. Migraine & Seizure Medications That Block Calcium’s Entry
Here we’re talking about some anticonvulsants. Look in your box for phenytoin, carbamazepine, or phenobarbital. Brand names might include Dilantin, Tegretol, or Gardinal. These are much more common medications than we imagine, often used for seizures, nerve pain, and even migraines.
What do they do to the bone? Something very treacherous. These medications are enzymatic inducers. They speed up the liver’s work so much that the liver starts destroying active vitamin D faster than the body can replace it. And without vitamin D, calcium simply cannot get into the bone. You can consume all the calcium in the world—milk, cheese, supplements—it won’t matter, because without vitamin D, the door to the bone is closed. When the body realizes calcium isn’t reaching the bone, it goes into emergency mode. It activates the parathyroid glands, which send a message: take calcium from the bones and put it in the blood. Your body starts robbing calcium from your bones to keep your blood levels stable. It’s as if your liver is devouring the very vitamin that protects your bones.
Did you find carbamazepine or phenytoin in your box? Now you understand why your neurologist may have ordered a vitamin D test. It wasn’t a random test. They were watching over your bones without you even realizing it. If you’ve been taking one of these medications for more than a year, talk to your neurologist. Ask about your vitamin D levels and whether your supplementation is adequate. And never stop an anticonvulsant on your own. Stopping suddenly can cause a severe seizure.
3. The Thyroid Medication That Can Double the Rate of Bone Loss
I need women to pay close attention here. I’m talking about thyroid hormones in excessive doses. Look in your box for levothyroxine. Brand names include Synthroid, Levoxyl, or Euthyrox. I’m almost certain many of you are holding this box right now.
Levothyroxine is one of the most prescribed drugs in the world. Millions of women over 50 take it every day for hypothyroidism. And let me tell you, the problem isn’t the medicine itself. Levothyroxine is an excellent drug. When the dose is right, it protects, it balances, it’s necessary. The problem is the dose. When the dose is higher than necessary, a condition we call iatrogenic hyperthyroidism (meaning it’s caused by the prescribed treatment), the excess thyroid hormone accelerates the bone remodeling cycle. And when I say accelerates, imagine this: instead of the bone rebuilding at a normal pace, the demolition team starts working at double speed. The construction team can’t keep up. The result is bone being destroyed faster than it’s being formed, every single day, silently.
Are you holding Puran T4 or Synthroid? Then answer me this: when was the last time you had your TSH checked? When was the last time your doctor re-evaluated your dose? Because many, and I mean many, women start on a dose and nobody adjusts it for 5, 8, or 10 years. The dose that was right at 55 might be too high at 65, and the excess is accelerating bone demolition without you feeling a thing. Your mission: go to your endocrinologist and ask, “Doctor, is my dose still appropriate? Do we need to re-evaluate?”
2. The Common Steroid That Kills Your Bone-Building Cells
Everyone knows this one. I’m talking about glucocorticoids, the famous corticosteroids. Look in your box for prednisone, prednisolone, dexamethasone, or deflazacort. Brand names include Meticorten, Prednicen, Decadron, or Calcort. This is the most well-known bone destroyer in medicine. It’s no secret; any doctor knows. But what many people don’t know is the speed at which it acts.
Corticosteroids are the most common cause of drug-induced osteoporosis worldwide. The medication is a triple threat. First, they kill osteoblasts, the builders, directly inhibiting new bone formation. The builders are sent home. Second, they reduce calcium absorption in the intestine. So even if you eat well, the calcium doesn’t get absorbed properly. Third, they increase calcium loss through the kidneys. Your body flushes calcium out in the urine. It’s a three-pronged attack.
And the most frightening part: bone density loss can begin in just three to six months of continuous use. Months, not years. And here’s the part that surprises many people. “Oh, Dr. Andre, but I don’t take prednisone.” What about that injection the orthopedist gave you for your back, knee, or shoulder pain? Often, that injection is a corticosteroid. The golden rule for corticosteroids is the lowest possible dose for the shortest possible time, and never stop it abruptly. Weaning must be done by a doctor.
1. The Acid Reflux Pill That Millions Take, Silently Crushing Their Bones
