I have been using vivelle dot 0.75mg for about 9 years, is that dangerous?

It would be best for you to talk to your doctor.

While there are some benefits of estrogen therapy, there are also certainly some risks.

From the prescribing information at http://www.vivelledot.com/Files/PDF/PrescribingInformation.pdf
"... Long-term, continuous administration of estrogen, with and without progestin, in
women with and without a uterus, has shown an increased risk of endometrial cancer, breast cancer, and ovarian cancer... "

Expand this post...

"... Most studies show no significant increased risk associated with the use of estrogens for less than 1 year. The greatest risk appears to be associated with prolonged use with increased risks of 15- to 24-fold for five to ten years or more, and this risk has been shown to persist for at least 8 to15 years after estrogen therapy is discontinued. Clinical surveillance of all women taking estrogen/progestin combinations is important. Adequate diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal
bleeding. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent
estrogen dose. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer... "

You may find this information on the Vivelle Dot website helpful...
http://www.vivelledot.com/Consumer/AboutEstrogenTherapy/Benefits-Risks.aspx

Weigh the Risks & Benefits of Estrogen Therapy (ET)

Before deciding on your course of treatment, it’s important to evaluate the risks and benefits. Make sure to consult with your doctor to find a treatment that’s right for you.

Risks of Estrogen Therapy
Estrogens increase the chances of getting cancer of the uterus (womb). You should report any unusual vaginal bleeding right away while you are taking estrogens. Vaginal bleeding after menopause may be a warning sign of cancer of the uterus (womb).

Do not use estrogens (with or without progestins) to prevent heart disease, heart attacks or strokes. Using estrogens (with or without progestins) may increase your chances of getting heart attacks, strokes, breast cancer and blood clots. Using estrogens may increase your risk of dementia (decline in memory and thinking skills).

Estrogen Therapy should not be used if you:

* Have unusual vaginal bleeding
* Currently have or have had certain cancers, including cancer of the breast or uterus
* Had a stroke or heart attack in the recent past (for example, in the past year)
* Currently have or have had blood clots
* Currently have or have had liver problems
* May be pregnant

Common side effects of estrogen therapy include headache, breast pain, irregular vaginal bleeding, stomach cramps, bloating, nausea, vomiting and hair loss.

Benefits of Estrogen Therapy
Estrogen therapy can help reduce moderate to severe hot flashes; treat moderate to severe dryness, itching and burning in or around the vagina; and help reduce your chances of getting osteoporosis (thin, weak bones). Vivelle-Dot® 0.025 mg/day is only used to prevent osteoporosis from menopause. If you use Vivelle-Dot only to treat your dryness, itching, and burning in and around your vagina or if you use Vivelle-Dot only to prevent osteoporosis from menopause, talk with your healthcare professional about whether a different treatment or medicine without estrogens might be better for you.