Breast tanner stages are developmental, not size!

For some reason almost every post on asks what their tanner stage is. Even if you don’t ask your tanner stage, someone will be compelled to tell you anyway in the comments.

Listen folks… Breast Tanner Scale is developmentally based, not size based. It’s not something interpretive, it is a physiological stage of development. Please refer to the chart below:

  • Tanner 1 is where you start before HRT (hormone replacement therapy).
  • Tanner 2 is where you will be at within 1-3 months most likely. Basically your areola is bigger but not much else going on.
  • Tanner 3 is when the breast tissue is getting noticeable; you can feel a mound start, but there isn’t much separation from the rest of the chest.
  • Tanner 4 is where the areola forms a secondary mount on top of the breast mound. This explicit characteristic is only found in about half of people growing breasts; so if you miss it, don’t stress out. Most likely you will have pointy breasts at this stage even without the secondary mound.
  • Tanner 5 is a fully formed mature breast. Notice how Tanner 4 is kind of pointy? Tanner 5 is filled in and rounded.

When I posted my own 6 month breast timeline, someone actually challenged my assertion that I was Tanner 3 based on size:

So keep in mind before HRT, I was Tanner 1 by default. At 1 month I had increased nipple size and elevation; a clear Tanner 2. At 6 months I still didn’t have a secondary nipple mound, which may or may not matter (only 1 in 2 people get it), but it is a clear Tanner 3 based upon contour of the breast mound. In fact, it is quite an advanced Tanner 3.

At around 8 months I entered Tanner 4 because I had the formation of a secondary elevation of the areola. What’s next? Tanner 5.

  1. Can you reach Tanner 5 without progesterone? In theory yes:

Progesterone is used as a component of feminizing hormone therapy for transgender women in combination with estrogens and antiandrogens.[52][18] However, the addition of progestogens to HRT for transgender women is controversial and their role is unclear.[52][18] Some patients and clinicians believe anecdotally that progesterone may enhance breast development, improve mood, and increase sex drive.[18] However, there is a lack of evidence from well-designed studies to support these notions at present.[18] In addition, progestogens can produce undesirable side effects, although bioidentical progesterone may be safer and better tolerated than synthetic progestogens like medroxyprogesterone acetate.[52][53]

Because some believe that progestogens are necessary for full breast development, progesterone is sometimes used in transgender women with the intention of enhancing breast development.[52][54][53] However, a 2014 review concluded the following on the topic of progesterone for enhancing breast development in transgender women:[54]

Our knowledge concerning the natural history and effects of different cross-sex hormone therapies on breast development in [transgender] women is extremely sparse and based on low quality of evidence. Current evidence does not provide evidence that progestogens enhance breast development in [transgender] women. Neither do they prove the absence of such an effect. This prevents us from drawing any firm conclusion at this moment and demonstrates the need for further research to clarify these important clinical questions.[54]

Typically the rule of thumb for when to take Progesterone is at or after 1 year to allow full ductal breast development to take place and avoid stunting. I don’t have a citation for this, but this timeline is widely mentioned.

I hope this article helps clarify the Tanner scale in relation to breast development a little more. I’m very tired of everyone asking about their tanner stage when it is developmental and not really a guessing game based on size of breast.

One thought on “Breast tanner stages are developmental, not size!

  1. With all the natural variation in size and shapes of breasts of adults, I have a hard time understanding how one, in a photograph, tells the difference between a fully adult breast – that is smaller and flatter than average – and a breast of similar shape and size that is still growing (somewhere in puberty).
    If there is young model with tiny breasts – how do I know if it’s a minor or an adult?

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