If perimenopause has you feeling off physically, mentally, and emotionally, you aren’t imagining it. Here are the hormones I test and the ranges I actually look for.
If your labs are ‘normal’ but you feel anything but, this is the testing framework I use with my perimenopause patients.
If you’re somewhere in your late thirties or forties and your body suddenly feels like it’s running on a different operating system, you’re not making it up. The sleep that used to come easily, the mood that used to feel stable, the cycle that used to be predictable, the energy that used to show up on command – all of it can start to shift in perimenopause, often years before anyone bothers to call it that. The frustrating part is that most women are told their labs look fine, when the real issue is that standard reference ranges tell you what’s average, not what’s optimal.
In my practice, I lean on a specific set of labs to understand what’s actually happening hormonally during this transition. Below is the framework I walk patients through – which hormones to test, when to time them, and the ranges I’m looking for when I’m working toward symptom relief and long-term health.
Estradiol (E2): The Estrogen That Drives Most Symptoms
Estradiol is the most potent form of estrogen and the one most tightly connected to mood, sleep, skin, bones, and vaginal tissue. I order a serum estradiol, and if a woman is still cycling, I prefer to draw it on days 2 through 4 of her cycle for a cleaner baseline. In perimenopause, I’m generally aiming for an E2 in the range of about 100 to 250 pg/mL for symptom relief and brain and bone support. Levels under 30 pg/mL often track with hot flashes, insomnia, and vaginal dryness.
One important caveat: estradiol swings dramatically in perimenopause, so a single number isn’t always definitive. What I care about is the pattern – consistently low E2 paired with real symptoms is often what supports a treatment decision, not a one-time snapshot.
Progesterone: The First to Decline
Progesterone is the counterbalance to estrogen. It calms the nervous system, supports sleep, eases anxiety, and keeps cycles regular – and it almost always starts dropping before estrogen does. I check a serum progesterone around day 21 of the cycle (mid-luteal phase) in women who are still ovulating. A mid-luteal progesterone above 10 ng/mL tells me ovulation happened, while a value under 5 ng/mL often points to an anovulatory cycle, which becomes increasingly common in perimenopause.
When progesterone is low or inconsistent, I tend to see the classic cluster: worsening PMS, fragmented sleep, and periods that are either heavier, closer together, or completely unpredictable.
FSH and LH: Markers of Ovarian Aging
FSH, or follicle stimulating hormone, is the signal your pituitary sends to your ovaries to make estrogen. As the ovaries become less responsive, FSH climbs – which is why it’s used as a marker of ovarian aging. Generally I think of serum FSH this way:
- Under 10 mIU/mL – premenopausal
- 10 to 25 mIU/mL – perimenopausal range
- Above 30 to 40 mIU/mL – suggests menopause, especially when estradiol is also low
That said, FSH fluctuates wildly during the transition, so I never interpret it on its own. It’s a piece of the picture alongside symptoms and the rest of the panel. LH, luteinizing hormone, surges before ovulation and can stay elevated or become erratic in perimenopause. Values often above 20 IU/L can suggest a peri- or menopausal state, and LH is most useful when paired with FSH to assess overall ovarian function.
Testosterone and DHEA-S: The Often-Missed Pair
Testosterone doesn’t get nearly enough attention in women, but it drives libido, energy, motivation, mood, and lean muscle. It declines gradually with age and can drop further with stress, hormonal birth control, or illness. To really see what’s going on, I run total testosterone, free testosterone (which is the more clinically meaningful number), and DHEA-S, the adrenal precursor.
The ranges I target in perimenopausal women:
- Free testosterone: around 1.0 to 2.2 pg/mL, depending on the lab
- Total testosterone: 20 to 60 ng/dL is typical
- DHEA-S: roughly 150 to 250 mcg/dL, varying by age
Low testosterone frequently flies under the radar because total T can look acceptable while free T and DHEA-S tell a very different story. If you’ve only had a total number checked, you don’t have the full picture.
Thyroid: The Great Mimicker
Thyroid dysfunction can imitate or amplify almost every perimenopausal symptom – fatigue, weight changes, mood swings, hair thinning, and irregular cycles. A standalone TSH is not enough. I order a complete thyroid panel including TSH, free T3, free T4, and thyroid antibodies (TPO and TgAb).
The ranges I use clinically:
- TSH: 0.5 to 2.0 mIU/L
- Free T3: 3.0 to 4.0 pg/mL
- Free T4: 1.0 to 1.4 ng/dL
- TPO and TgAb: should be negative or low; elevated antibodies can suggest autoimmune thyroiditis
Even results flagged as “normal” can be suboptimal. If your TSH is above 2.5 and your symptoms haven’t budged, that is worth a deeper look rather than a dismissal.
Additional Labs Worth Running
Depending on the clinical picture, there are a few more tests I like to add. Salivary cortisol gives me a window into adrenal function, which matters because chronic stress can worsen virtually every perimenopausal symptom. Sex hormone-binding globulin (SHBG) is useful because it influences how much free estrogen and testosterone are actually available to your tissues. And I always check 25-OH vitamin D – I aim for an optimal range of 60 to 80 ng/mL, since vitamin D plays a real role in hormone balance, mood, and immunity.
Normal Isn’t the Same as Optimal
This is the piece I want every woman reading this to internalize: lab ranges show you what’s average in the general population. What you’re actually aiming for is what’s optimal for you. Hormones don’t work in isolation – they operate like a symphony, and perimenopause can throw that symphony badly out of tune.
If you’re navigating any combination of:
- Sleep disruption
- Brain fog
- Low libido
- Mood changes
- Cycle chaos
- Vaginal dryness
- Anxiety or fatigue
you don’t have to keep guessing, Googling symptoms at midnight, or accepting “your labs are normal” when your body is clearly telling you otherwise. Perimenopause isn’t the end of feeling like yourself – it’s an invitation to finally understand your hormones, your labs, and the order in which your body actually needs support.
Go deeper
If you want to go deeper into how to actually address perimenopause symptoms through a comprehensive framework, “The Perimenopause Protocol” walks you through the full protocol Lexi uses in practice to help women navigate this transition.
Lexi Yoo
Lexi Yoo, NP is a functional medicine nurse practitioner and national speaker specializing in hormones, gut health, and longevity. She helps women understand what their bodies are telling them - and turn it into a plan that actually works.
