$18.00
Priced per marker, with baseline labs included. You’ll see your total before you pay.
Bone health
CTx test
C-telopeptide. Bone resorption marker that can show how fast bone is being broken down.
At a glance
In about 5 days
Most results are ready in about 5 days. Some specialty markers can take up to 21 days.
Fast for 8–12 hours first. Best at a set time of day or cycle day
Contact us before your draw if you’re not sure.
Walk in at Quest
Your lab order arrives by email. Most Quest locations take walk-ins, so bring it with a photo ID.
What it measures
Your body is always breaking down old bone and building new bone. CTx is a scrap of bone protein released during breakdown, so it can show how quickly bone is being cleared away.
Why it matters for women
Falling estrogen around menopause can speed up bone breakdown, a big reason osteoporosis is more common in women. Alongside a bone density scan, CTx can help show how fast that’s happening and how your bones respond over time. Levels can swing with time of day and meals, so it may be drawn in the morning before eating.
You might check it if…
- you’re in perimenopause or past menopause
- a bone density scan showed thinning bones
- you broke a bone in a minor fall
- a doctor is tracking how your bones change over time
What your result may mean
High CTx: what it may mean
High CTx may mean your bones are being broken down faster than usual (bone resorption). It can happen after menopause, when falling estrogen can speed up bone loss, and with osteoporosis, an overactive thyroid (hyperthyroidism), overactive parathyroid glands (hyperparathyroidism) or other untreated bone disease. A recent fracture can raise it for a while too. Bone loss can be silent until a bone breaks. Levels can swing with time of day and meals, so a fasting morning sample may be easier to compare over time.
Low CTx: what it may mean
Low CTx may mean bone breakdown has slowed down. It can be an expected effect of osteoporosis medicines such as bisphosphonates, and a clinician may use it to see how treatment is working. Menopausal hormone therapy can lower it too. Because CTx can drop after eating and later in the day, a sample taken after a meal may read low. A low value can't show that your bones are strong, so it may be read with a bone density scan.
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These notes provide context and do not diagnose a condition. Not yet available in NY, NJ, RI, HI, ND, SD or WV.