> **[Progesterone and [[thyroid]]]** Sometimes progesterone can cause an underactive enlarged [[thyroid]] gland to begin secreting, temporarily producing mild [[hypothyroidism]] while the gland returns to a normal size. Supplemental progesterone can reduce excessive cortisol production. > > Since progesterone helps the [[thyroid]] to secrete, and helps the liver to regulate glucose and convert T4 to T3, women who are low in progesterone usually have hypothyroid symptoms (because of insufficient T3), including high cortisol, which promotes the synthesis of estrogen (in several ways, but never from progesterone). Cortisol is made from progesterone, but increasing the supply of progesterone reliably lowers cortisol synthesis, acting on the [[brain]], pituitary, and adrenal glands. Progesterone, by many mechanisms, including its antagonism to cortisol, lowers the amount of estrogen in cells (causing the estrogen-binding proteins to be degraded, inhibiting the enzymes that release estrogen from the sulfates and glucuronides, and activating the enzymes that detoxify estrogen). So I think the symptoms of increased estrogen and cortisol are the result of either extraneous ingredients in the creams, or from using it at the wrong time, for example, too early, triggering premature ovulation. Supplementing a small amount of T3, Cytomel or Cynomel, usually stops symptoms such as breast pain, irritability, and restless energy, in less than an hour. > I think continuing the progesterone would help to normalize [[thyroid]] responses. If you adjust the [[thyroid]] dose every two weeks according to how you feel, and according to your temperatures and [[pulse]] rate, there should be a point where your cycle is right, without needing progesterone. During the winter the need for [[thyroid]] is higher, because of the short days, so it's important to watch for decreasing need when the days are longer in the spring. > **[Starting Dose]** It's usual to start with just a couple of drops of progesterone; depending on your symptoms, that amount could be repeated, as needed. [[thyroid]] tends to lower cholesterol, converting some of it to progesterone. Both cholesterol and progesterone are involved in the response to [[thyroid]]. > **[Rubbing on gums or swallowing?]** Some will enter your blood stream very quickly from the mouth membranes, but taking it with food the effect will be more gradual and prolonged. > **[Surgical Menopause]** I think it's most effective when you take it cyclically; imitating the menstrual cycle, with two week on and two off, would be good, unless you are using it to control some symptom. > **[Could progesterone turn into estrogen?]** Progesterone won't turn into estrogen, but along with [[thyroid]] and [[aspirin]] it will tend to reduce the amount of estrogen in the body. If you have symptoms, you could adjust the dose according to the effect; I have seen some people start recovering immediately with just 10 mg of progesterone, but it depends on the balance of other hormones. < See also [#Menses](https://archive.ph/OJZkW#Menses). > > [I've been using progesterone strictly for anxiety and pregnenolone for stress (learned helplessness); do you view the use progesterone as appropriate in a hyperthyroid state, or would it just make you even more hyperthyroid and contribute to the anxiety?] If your [[thyroid]] gland is enlarged, progesterone’s normalization of function can lead to a few weeks of increased [[thyroid]] activity while the gland unloads excess colloid. Some antiserotonin drugs can be hard on the heart. [Source](https://lowtoxinforum.com/threads/ray-peat-email-advice-depository.1035/post-224612) > [Using Progest-E ongoing or cyclically for post-menopausal women.] If there are symptoms, repeating a small dose will usually relieve them. If a person is hypothyroid, the tissues are likely to contain more estrogen, making them less sensitive to progesterone, so it’s good to be aware of indicators of [[thyroid]] status, such as body temperature, pulse rate, and blood pressure. Some people take a little every day to prevent symptoms, but (especially when there’s good [[thyroid]] function) its effectiveness is greatest when it’s used cyclically. [Source](https://lowtoxinforum.com/threads/ray-peat-email-advice-depository.1035/post-226020)