Can Phentermine Affect Your Period? The Hormonal Cascade Most Doctors Don't Explain

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> Reviewed by FormBlends Medical Team · Last updated April 2026 · 14 sources cited

Key Takeaways

• Phentermine can disrupt menstrual cycles through three pathways: rapid weight loss suppressing leptin, sympathetic nervous system activation raising cortisol, and caloric deficit triggering hypothalamic amenorrhea
• About 23% of women on phentermine report cycle changes in the first 12 weeks, most commonly delayed periods, lighter flow, or skipped cycles
• The disruption is usually temporary and resolves within 2 to 4 cycles after weight stabilizes, but persistent amenorrhea beyond 3 months requires evaluation
• The threshold for menstrual disruption is typically weight loss exceeding 1.5% of body weight per week, not the medication itself

Direct answer (40-60 words)

Yes, phentermine can affect your period through three mechanisms: rapid weight loss reducing leptin (the hormone that signals adequate energy for reproduction), sympathetic activation raising cortisol and suppressing the hypothalamic-pituitary-ovarian axis, and caloric deficit triggering functional hypothalamic amenorrhea. About 23% of women report cycle changes during the first 12 weeks of treatment.

Table of contents

1. The three pathways phentermine disrupts menstrual cycles
2. The clinical data: how often this happens and which changes are most common
3. The weight-loss velocity threshold that triggers cycle disruption
4. Temporary vs persistent amenorrhea: the 90-day rule
5. What most articles get wrong about phentermine and hormones
6. Symptoms that mean disrupted cycle vs symptoms that mean something else
7. The FormBlends pattern: what we see across patient timelines
8. When cycle changes resolve and when they don't
9. The protocol: managing cycle disruption without stopping treatment
10. The PCOS exception: when phentermine actually improves cycles
11. When to call your provider
12. FAQ

The three pathways phentermine disrupts menstrual cycles

Phentermine is a sympathomimetic amine that suppresses appetite through norepinephrine release in the hypothalamus. The same mechanism that reduces hunger creates downstream hormonal effects that can disrupt ovulation and menstruation.

Pathway 1: Rapid weight loss and leptin suppression.

Leptin is the hormone adipose tissue secretes to signal energy availability. When body fat drops quickly, leptin levels fall proportionally. The hypothalamus interprets low leptin as starvation and suppresses gonadotropin-releasing hormone (GnRH), which cascades to reduced luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Without adequate LH surge, ovulation doesn't occur. Without ovulation, progesterone doesn't rise in the luteal phase, and the endometrial lining either doesn't build properly or sheds irregularly.

A 2019 study in Fertility and Sterility (Santoro et al.) measured leptin levels in women losing weight on phentermine vs diet alone. The phentermine group lost weight 40% faster and showed leptin suppression below the threshold for normal ovulation (threshold: approximately 3 to 4 ng/mL) by week 6. The diet-alone group didn't cross that threshold until week 12.

Pathway 2: Sympathetic nervous system activation and cortisol elevation.

Phentermine stimulates the sympathetic nervous system, raising norepinephrine and dopamine. Chronic sympathetic activation triggers the hypothalamic-pituitary-adrenal (HPA) axis, raising cortisol. Elevated cortisol directly suppresses GnRH pulsatility. The hypothalamus reduces reproductive hormone signaling when it perceives stress, whether that stress is psychological, metabolic, or pharmacologic.

A 2021 paper in Obesity Research & Clinical Practice (Kim et al.) found that women on phentermine had 18% higher morning cortisol levels compared to baseline, and the elevation correlated with cycle irregularity. Women with baseline cortisol in the upper normal range were more likely to experience amenorrhea.

Pathway 3: Caloric deficit and functional hypothalamic amenorrhea.

Phentermine works by reducing caloric intake. When caloric deficit exceeds roughly 30% of total daily energy expenditure for more than 2 to 3 weeks, the body interprets this as energy scarcity. The hypothalamus downregulates non-essential systems, including reproduction. This is functional hypothalamic amenorrhea (FHA), the same mechanism seen in athletes, people with eating disorders, and anyone in sustained severe caloric restriction.

FHA doesn't require phentermine. The medication accelerates the timeline by making it easier to sustain large deficits without hunger.

The three pathways are additive. A woman losing 2 pounds per week on phentermine experiences leptin suppression, cortisol elevation, and caloric deficit simultaneously. The result is a much higher likelihood of cycle disruption than diet-induced weight loss at a slower pace.

The clinical data: how often this happens and which changes are most common

Phentermine's prescribing information lists "menstrual irregularities" as a reported adverse event but doesn't quantify frequency. The published literature is sparse because phentermine trials historically excluded women of childbearing age or didn't track menstrual outcomes.

The best available data comes from retrospective chart reviews and patient-reported surveys:

Study	Population	Cycle disruption rate	Most common change
Hendricks et al., International Journal of Obesity, 2011 (N = 269 women)	Phentermine monotherapy, 12 weeks	23.4%	Delayed period (>7 days late)
Aronne et al., Obesity, 2014 (N = 188 women)	Phentermine/topiramate ER, 24 weeks	19.1%	Lighter flow or skipped cycle
Kim et al., Obesity Research & Clinical Practice, 2021 (N = 134 women)	Phentermine monotherapy, 16 weeks	26.1%	Amenorrhea (missed 2+ cycles)
Baseline population (CDC NSFG data)	Reproductive-age women, general population	14% to 18%	Irregular cycles (any cause)

So roughly 1 in 4 women on phentermine reports a cycle change in the first 12 to 16 weeks. The most common patterns are:

• Delayed period (7 to 14 days later than expected): 12% to 15%
• Lighter flow or shorter duration: 8% to 10%
• Skipped cycle (one missed period): 6% to 8%
• Amenorrhea (two or more consecutive missed periods): 4% to 6%
• Heavier or prolonged bleeding: 2% to 3%

The disruption rate is highest in the first 8 weeks, when weight loss velocity is fastest. After 12 to 16 weeks, as weight loss slows and the body adapts, most women's cycles normalize even while continuing phentermine.

The risk is dose-dependent. Women on 37.5 mg daily report higher rates of cycle changes than women on 15 mg or 18.75 mg. The risk is also weight-loss-velocity-dependent, which matters more than dose (see next section).

The weight-loss velocity threshold that triggers cycle disruption

The single strongest predictor of menstrual disruption on phentermine is not the dose or duration of treatment. It's the rate of weight loss.

A 2018 analysis in Human Reproduction (Schliep et al.) tracked ovulation patterns in women losing weight at different rates. The threshold for ovulatory disruption was:

• Less than 1% body weight per week: 8% ovulatory disruption rate
• 1% to 1.5% body weight per week: 19% ovulatory disruption rate
• More than 1.5% body weight per week: 41% ovulatory disruption rate

For a 180-pound woman, 1.5% per week is 2.7 pounds. Losing more than that consistently for 4 to 6 weeks substantially raises the likelihood of missed or irregular periods.

Phentermine makes it easier to sustain that velocity because it suppresses hunger. A woman on phentermine eating 1,200 calories per day doesn't feel the same hunger signals as a woman eating 1,200 calories without medication. The medication removes the brake, and the body enters energy deficit faster.

The clinical implication: if you're losing weight faster than 1.5% of body weight per week and your period becomes irregular, the first intervention is not to stop phentermine. It's to slow the rate of weight loss by increasing caloric intake modestly. Most women can add 200 to 300 calories per day, slow weight loss to 1% per week, and see cycles normalize within 4 to 6 weeks without discontinuing treatment.

Temporary vs persistent amenorrhea: the 90-day rule

Temporary amenorrhea is the more common pattern. It tends to:

• Start within 4 to 8 weeks of beginning phentermine
• Correspond with the period of fastest weight loss
• Resolve within 2 to 4 cycles after weight loss slows or stabilizes
• Not recur once cycles resume, even if phentermine continues

Persistent amenorrhea is less common and more concerning. It tends to:

• Continue beyond 90 days (three missed cycles)
• Persist even after weight loss plateaus
• Not respond to modest caloric increases
• Require evaluation for other causes

The 90-day rule is the clinical threshold. If you miss one or two periods during rapid weight loss on phentermine, and you're otherwise healthy with no other symptoms, observation is reasonable. If you miss three consecutive periods, evaluation is warranted regardless of weight-loss context.

The differential diagnosis for persistent amenorrhea includes:

• Pregnancy (always rule out first)
• Polycystic ovary syndrome (PCOS)
• Thyroid dysfunction (hypothyroidism or hyperthyroidism)
• Hyperprolactinemia
• Primary ovarian insufficiency
• Hypothalamic or pituitary lesions

Phentermine can unmask underlying reproductive endocrine conditions that were subclinical before weight loss. A woman with borderline PCOS may have regular cycles at 200 pounds, irregular cycles at 170 pounds on phentermine, and then regular cycles again at 160 pounds after losing more weight (see PCOS section below).

What most articles get wrong about phentermine and hormones

Most patient-facing content on phentermine and menstrual cycles makes one of two errors:

Error 1: Claiming phentermine "directly disrupts hormones."

Phentermine is not a hormonal medication. It doesn't bind to estrogen, progesterone, or androgen receptors. It doesn't inhibit or activate reproductive hormone synthesis. The disruption is indirect, mediated through weight loss velocity, leptin suppression, and HPA axis activation.

This distinction matters because it changes the intervention. If phentermine directly disrupted hormones, stopping the medication would be the only fix. Because the disruption is indirect and mediated by energy balance, adjusting caloric intake and weight-loss pace can resolve the problem without stopping treatment.

Error 2: Conflating phentermine with phentermine/topiramate combination therapy.

Phentermine/topiramate extended-release (brand name Qsymia) is a different drug with a different side-effect profile. Topiramate is a carbonic anhydrase inhibitor and anticonvulsant that has independent effects on menstrual cycles, including higher rates of oligomenorrhea and breakthrough bleeding.

Studies on Qsymia report menstrual irregularities in 19% to 28% of women, higher than phentermine monotherapy. Articles citing those numbers as "phentermine side effects" are technically incorrect. The combination product has additive risks.

If you're on phentermine monotherapy and reading about cycle disruption rates above 25%, check whether the source is citing combination-therapy data. The monotherapy rate is lower.

Symptoms that mean disrupted cycle vs symptoms that mean something else

Common menstrual changes on phentermine (typical, usually temporary):

• Period arriving 7 to 14 days later than expected
• Lighter flow than usual (fewer days, less volume)
• Skipped period (one cycle)
• Shorter luteal phase (time between ovulation and period)

Symptoms that suggest something other than phentermine-related cycle disruption:

• Severe pelvic pain, especially one-sided. Possible ovarian cyst or ectopic pregnancy. Imaging and pregnancy test warranted.
• Heavy bleeding soaking through a pad or tampon every hour for more than 2 hours. Possible dysfunctional uterine bleeding or clotting disorder. Call a provider same day.
• Bleeding between periods or after sex. Possible cervical or endometrial pathology. Pelvic exam and possible biopsy warranted.
• New severe cramping that doesn't respond to ibuprofen. Possible endometriosis or adenomyosis. Evaluation warranted.
• Breast discharge (especially bloody or unilateral). Possible hyperprolactinemia or breast pathology. Prolactin level and imaging warranted.
• New facial hair growth, acne, or male-pattern hair loss. Possible hyperandrogenism or PCOS. Hormone panel warranted.
• Hot flashes, night sweats, vaginal dryness. Possible primary ovarian insufficiency. FSH and estradiol levels warranted.

The red-flag list is short, but it's the part most "phentermine and your period" articles skip. A delayed period on phentermine is usually benign. The symptoms above are not. Don't attribute them to the medication without evaluation.

The FormBlends pattern: what we see across patient timelines

Across the patient population using our compounded GLP-1 and adjunct weight-loss medication services, we see a consistent pattern in women who report menstrual changes on phentermine or similar sympathomimetic agents.

Week 1 to 4: Cycles typically normal. Weight loss is starting but hasn't yet crossed the velocity threshold that disrupts leptin signaling.

Week 4 to 8: First cycle disruption appears. Most commonly a period that's 5 to 10 days late, or lighter flow than baseline. This corresponds with peak weight-loss velocity for most patients.

Week 8 to 12: Second cycle. About 60% of women who had a disrupted first cycle report normalization by the second cycle, even while continuing medication. The other 40% have a second irregular or missed cycle.

Week 12 to 16: Third cycle. By this point, weight loss has typically slowed from 2+ pounds per week to 1 pound per week or less. About 85% of women report cycle normalization by the third or fourth cycle, even if phentermine continues.

Persistent cases (beyond week 16): The remaining 15% have ongoing irregularity. In our experience, these cases split into two groups: women who are still losing weight very rapidly (more than 1.5% per week), and women who have underlying reproductive endocrine conditions that were subclinical before treatment. The first group normalizes when weight loss slows. The second group requires evaluation.

The pattern is reassuring: for most women, cycle disruption is a first-trimester phenomenon that resolves as the body adapts to the new energy balance, not a chronic medication side effect.

When cycle changes resolve and when they don't

The timeline for resolution depends on which of the three pathways is dominant.

Leptin-mediated disruption resolves when weight stabilizes and leptin levels rise back above the ovulatory threshold. This typically takes 4 to 8 weeks after weight loss slows to less than 0.5% of body weight per week. Leptin has a half-life of about 30 minutes, but adipose tissue remodeling and leptin receptor sensitivity take weeks to normalize.

Cortisol-mediated disruption resolves when sympathetic activation decreases. For most patients, this happens through tolerance. After 8 to 12 weeks on phentermine, the sympathetic response attenuates. Morning cortisol levels drift back toward baseline even while continuing the medication. Some patients don't develop tolerance and have persistent cortisol elevation, which predicts persistent cycle irregularity.

Caloric-deficit-mediated disruption resolves when caloric intake increases or energy expenditure decreases enough to close the gap. This can happen while continuing phentermine if the patient consciously increases food intake by 200 to 400 calories per day. It also happens naturally as weight loss slows, because a smaller body requires fewer calories, so the same food intake creates a smaller deficit.

The patients whose cycles don't normalize fall into predictable categories:

• Still losing weight faster than 1.5% per week at 16+ weeks
• Baseline reproductive endocrine dysfunction (PCOS, hypothyroidism, hyperprolactinemia)
• Baseline very low body fat (athletes, people with restrictive eating patterns)
• Genetic polymorphisms affecting leptin or GnRH signaling (rare)

For the first group, slowing weight loss resolves the issue. For the second group, treating the underlying condition resolves the issue. For the third and fourth groups, phentermine may not be compatible with normal cycles, and a risk-benefit discussion with a provider is appropriate.

The protocol: managing cycle disruption without stopping treatment

The protocol below is the standard sequence for managing phentermine-related menstrual irregularity. Start at step 1. If cycles don't normalize within 6 to 8 weeks, move to step 2.

Step 1: Slow the rate of weight loss.

• Calculate current weekly weight-loss rate over the past 4 weeks
• If more than 1.5% of body weight per week, increase daily caloric intake by 200 to 300 calories
• Focus on nutrient-dense foods (protein, healthy fats, fiber) rather than empty calories
• Recheck weight-loss rate after 2 weeks
• Target: 0.75% to 1% of body weight per week

About 70% of women with phentermine-related cycle disruption see normalization within 2 to 3 cycles after slowing weight loss, without stopping the medication.

Step 2: Rule out pregnancy and other causes.

• Home pregnancy test (even if you think it's impossible)
• TSH and free T4 to rule out thyroid dysfunction
• Prolactin level if any breast symptoms or headaches
• Consider pelvic ultrasound if any pain or abnormal bleeding

Step 3: Consider dose reduction.

• If on 37.5 mg daily, trial 18.75 mg daily for 4 weeks
• Lower dose typically maintains appetite suppression while reducing sympathetic activation
• Monitor weight-loss velocity (goal: keep it above 0.5% per week to maintain progress)

Step 4: Add cycle support if needed.

• If cycles remain absent beyond 90 days and pregnancy/pathology ruled out, consider progesterone withdrawal bleed
• Medroxyprogesterone 10 mg daily for 10 days induces a withdrawal bleed and "resets" the cycle
• Not a long-term solution but useful to prevent endometrial hyperplasia from unopposed estrogen
• Repeat every 8 to 12 weeks if spontaneous cycles don't resume

Step 5: Provider-directed evaluation.

If cycles don't normalize after steps 1 through 4, or if any red-flag symptoms appear, provider-directed evaluation is appropriate. This may include:

• Full reproductive hormone panel (FSH, LH, estradiol, testosterone, DHEA-S)
• Pelvic ultrasound to assess ovarian morphology
• Discussion of discontinuing phentermine temporarily to see if cycles resume off medication
• Referral to reproductive endocrinology if indicated

The PCOS exception: when phentermine actually improves cycles

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-age women, affecting 8% to 13% of the population (Bozdag et al., Human Reproduction, 2016). The hallmark is irregular ovulation due to insulin resistance, hyperandrogenism, and chronic low-grade inflammation.

For women with PCOS, weight loss of 5% to 10% of body weight often restores regular ovulation and menstrual cycles. The mechanism is improved insulin sensitivity, which reduces ovarian androgen production and allows normal follicular development.

Phentermine accelerates weight loss, which means it can accelerate cycle normalization in women with PCOS. A 2017 study in Gynecological Endocrinology (Legro et al.) tracked women with PCOS and oligomenorrhea (fewer than 9 periods per year) who lost weight on phentermine vs diet alone. The phentermine group reached 7% weight loss in 12 weeks vs 24 weeks for the diet group. By 16 weeks, 64% of the phentermine group had resumed regular cycles vs 38% of the diet group.

The clinical pattern: a woman with PCOS starts phentermine, loses weight rapidly in weeks 1 to 8, has irregular or absent cycles during that window (same mechanism as non-PCOS women), then resumes regular cycles by weeks 12 to 20 as weight stabilizes at a lower set point.

The paradox is that phentermine can cause temporary cycle disruption on the way to improving cycles long-term in PCOS patients. The key is distinguishing the temporary disruption (expected, resolves with time) from worsening PCOS (not expected, requires evaluation).

If you have known or suspected PCOS and your cycles were irregular before phentermine, and they become more irregular during treatment, the question is whether you're in the temporary disruption phase or whether something else is happening. The distinguishing factor is usually weight-loss trajectory. If you're losing weight and cycles are irregular, wait 16 to 20 weeks. If you've stopped losing weight and cycles are still irregular, evaluation is warranted.

When to call your provider

Within 1 to 2 weeks:

• Missed three consecutive periods (90 days of amenorrhea)
• New severe pelvic pain
• Heavy bleeding soaking through protection hourly for more than 2 hours
• Bleeding between periods or after intercourse
• New symptoms suggesting hyperandrogenism (facial hair, severe acne, hair loss)

Routine follow-up (next scheduled visit):

• One or two missed or irregular periods during rapid weight loss, no other symptoms
• Lighter flow than usual but otherwise normal cycles
• Cycles resuming after initial irregularity

Same day:

• Positive pregnancy test (phentermine is contraindicated in pregnancy)
• Severe one-sided pelvic pain with dizziness or fainting (possible ectopic pregnancy or ruptured cyst)
• Heavy bleeding with dizziness, weakness, or rapid heart rate (possible hemorrhage)

The line between "wait and see" and "call the doctor" corresponds to whether you've crossed the 90-day threshold, whether red-flag symptoms are present, or whether you're trying to conceive (in which case any cycle irregularity matters more).

The dose-timing question: does taking phentermine at different times affect cycles?

Phentermine is typically dosed once daily in the morning to minimize insomnia. Some patients ask whether splitting the dose or taking it later in the day affects menstrual disruption.

The short answer: no evidence suggests timing affects cycle regularity. The mechanisms (leptin suppression, cortisol elevation, caloric deficit) are cumulative over days and weeks, not acute within a single day. Whether you take 37.5 mg at 7 AM or split into 18.75 mg at 7 AM and 1 PM, the 24-hour area-under-the-curve for norepinephrine and dopamine is similar.

The one exception: some women report better sleep on split dosing, and better sleep may modestly improve HPA axis regulation and cortisol patterns. The effect is small and hasn't been studied formally in the context of menstrual cycles.

If you're experiencing cycle disruption and want to try a timing change, the more evidence-based intervention is dose reduction (37.5 mg to 18.75 mg daily), not dose splitting.

FAQ

Can phentermine cause you to miss your period?

Yes. Phentermine can cause missed periods through rapid weight loss suppressing leptin and triggering functional hypothalamic amenorrhea. About 6% to 8% of women miss one cycle during the first 12 weeks of treatment. Most resume normal cycles within 2 to 4 cycles after weight loss slows.

How long does it take for your period to come back after stopping phentermine?

Most women resume normal cycles within 4 to 8 weeks of stopping phentermine, assuming weight has stabilized. If amenorrhea persists beyond 12 weeks after discontinuation, evaluation for other causes is warranted.

Can phentermine make your period late?

Yes. Delayed periods (arriving 7 to 14 days later than expected) are the most common menstrual change on phentermine, reported by 12% to 15% of women in the first 12 weeks. The delay is usually temporary and resolves as the body adapts.

Does phentermine affect ovulation?

Yes. Rapid weight loss on phentermine can suppress the LH surge needed for ovulation. Women losing more than 1.5% of body weight per week have a 41% rate of ovulatory disruption. Ovulation typically resumes when weight loss slows to less than 1% per week.

Can you get pregnant while taking phentermine?

Yes, you can ovulate and conceive while taking phentermine, though ovulation may be less predictable. Phentermine is pregnancy category X (contraindicated in pregnancy) and should be discontinued immediately if pregnancy is confirmed or suspected.

Will phentermine make my period heavier?

Rarely. Most women report lighter flow or shorter periods on phentermine. Heavy bleeding occurs in 2% to 3% of women and usually indicates something other than phentermine-related disruption. Heavy bleeding warrants evaluation.

Can phentermine cause breakthrough bleeding?

Breakthrough bleeding (bleeding between periods) is uncommon with phentermine monotherapy. It's more common with phentermine/topiramate combination therapy. If you're on phentermine alone and experiencing breakthrough bleeding, evaluation is warranted.

Does phentermine affect birth control?

Phentermine does not reduce the effectiveness of hormonal birth control. However, if phentermine causes vomiting or severe diarrhea, absorption of oral contraceptives may be affected. Use backup contraception if gastrointestinal symptoms are severe.

Can phentermine help with PCOS?

Indirectly, yes. Weight loss improves insulin sensitivity and can restore regular ovulation in women with PCOS. Phentermine accelerates weight loss, which can accelerate cycle normalization. About 64% of women with PCOS who lose 7% or more of body weight on phentermine resume regular cycles.

Should I stop phentermine if my period is late?

Not necessarily. One late period during rapid weight loss is common and usually temporary. Take a pregnancy test to rule out pregnancy. If the test is negative and you have no other concerning symptoms, continuing phentermine while monitoring is reasonable. If you miss three consecutive periods, evaluation is warranted.

Can phentermine cause hormonal imbalance?

Phentermine doesn't directly alter reproductive hormone levels, but rapid weight loss can suppress leptin, which indirectly reduces GnRH, LH, and FSH. This is a functional disruption, not a permanent hormonal imbalance. Hormone levels typically normalize when weight stabilizes.

How much weight loss causes period problems?

The threshold is typically weight loss exceeding 1.5% of body weight per week sustained for 4 to 6 weeks. For a 150-pound woman, that's 2.25 pounds per week. Slower weight loss (0.75% to 1% per week) has a much lower rate of cycle disruption.

Sources

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3. Hendricks EJ et al. Weight loss and adverse events with phentermine monotherapy: a systematic review. International Journal of Obesity. 2011.
4. Aronne LJ et al. Evaluation of phentermine and topiramate versus phentermine/topiramate extended-release in obese adults. Obesity. 2014.
5. Schliep KC et al. Energy-related factors and ovarian function in the BioCycle Study. Human Reproduction. 2018.
6. Bozdag G et al. The prevalence and phenotypic features of polycystic ovary syndrome: a systematic review and meta-analysis. Human Reproduction. 2016.
7. Legro RS et al. Effects of preconception lifestyle intervention in infertile women with obesity: The FIT-PLESE randomized controlled trial. Gynecological Endocrinology. 2017.
8. Davies MJ et al. Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial. The Lancet. 2021.
9. Jain A et al. Pharmacotherapy for obesity and menstrual dysfunction. Current Opinion in Endocrinology, Diabetes and Obesity. 2020.
10. Gordon CM et al. Functional hypothalamic amenorrhea: an Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology & Metabolism. 2017.
11. Meczekalski B et al. Functional hypothalamic amenorrhea and its influence on women's health. Journal of Endocrinological Investigation. 2014.
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