Getting pregnant after using depot medroxyprogesterone acetate (the Depo shot) feels tricky when the shot’s goal is to switch off ovulation. Yet thousands of users move from injections to baby bumps each year. This guide explains why the shot delays fertility, the timelines backed by research, and the practical moves that lift your odds while you wait.
How The Shot Holds Back Ovulation
The 150-mg intramuscular version and the 104-mg subcutaneous version both flood the bloodstream with medroxyprogesterone, a synthetic progestin. That hormone binds to receptors in the brain and in the ovaries and stops the pulsatile release of gonadotropin-releasing hormone, luteinising hormone, and follicle-stimulating hormone, shutting down follicle growth and the mid-cycle surge that sparks ovulation.
A single injection keeps serum levels above the ovulation-blocking threshold of 0.1 ng/mL for at least 12–13 weeks. Package instructions set the next dose at week 12, yet data show a small risk of return of ovulation by week 14.
The table below summarises what researchers have tracked after standard dosing.
| Weeks Since Last Shot | Typical MPA Level | Ovulation Chance |
|---|---|---|
| 0-12 | >0.3 ng/mL | Minimal |
| 13-14 | ≈0.2 ng/mL | Low but rising |
| 15-28 | 0.05-0.1 ng/mL | Up to 5 % |
| >29 | <0.05 ng/mL | Depends on personal factors |
Can Pregnancy Happen Before You Stop The Shot?
Breakthrough ovulation is rare but not impossible. Studies estimate roughly 1–3 pregnancies per 100 users each year, mainly linked to late injections. If a dose slips past the 13-week window, sperm that survive up to five days could meet an unexpected egg.
Early Return Of Ovulation
Small pharmacokinetic trials found ovulation as early as week 15 in subcutaneous users. Body weight, injection site, and liver metabolism play roles, so two friends on the same schedule may not share the same hormone curve.
Spotting And Cycle Myths
Bleeding patterns give few clues. Many users have no periods at all, yet ovulation can still sneak back once serum progestin dips. Tracking cervical mucus or using ovulation predictor kits becomes useful once you approach the 15-week mark.
Average Wait Before Fertility Returns
Population data show half of former users conceive within ten months of their final shot. The average time to first ovulation ranges from five to seven months depending on dose strength. The NHS says cycles may take up to a year to stabilise for some.
Age, weight, and shot history matter. People under 25 and those with fewer than three total injections often resume ovulation sooner than long-term users in their thirties.
Step-By-Step Plan To Boost Your Chances
The Depo hormone clears only with time, yet you can stack the deck in your favour once you choose to grow your family.
1. Schedule Your Last Injection With A Conception Window In Mind
If you are still on time for the next shot, skip it and mark the calendar. Aim to begin active trying no sooner than three months later to allow hormone decay below the suppression line.
2. Track Hormones Rather Than Periods
Use luteinising-hormone urine strips from week 14 onward. A positive surge confirms the pituitary axis has restarted. Pair the strips with basal body temperature for cross-check. Record dates in a simple cycle log for future reference later.
3. Help Healthy Follicle Growth
Aim for steady sleep, balanced macronutrients, and stress-relief practices. Follicles thrive when insulin and cortisol stay in a moderate range, and those factors respond to diet and relaxation drills.
4. Time Intercourse Or Intrauterine Insemination
Once a clear LH surge appears, plan intercourse within the next 24–36 hours or discuss insemination timing with a fertility nurse.
The table below links common strategies with published data and realistic timelines.
| Action | Study Or Authority | Expected Timeline Shift |
|---|---|---|
| Skip final shot | Mayo Clinic overview | Ovulation possible in 15–20 weeks |
| Daily LH strips from week 14 | PubMed pharmacodynamics | Detect first cycle sooner |
| Weight-bearing exercise 3 times weekly | WHO guidance | May improve ovulatory progesterone |
Nutrition And Lifestyle Tweaks While You Wait
Eating iron-rich plants, oily fish, and dairy provides building blocks for oestrogen rebound. Add a prenatal multivitamin that supplies 400 µg of folate. Help bone density, often reduced on the shot, with weight exercises and vitamin D from sunlight or fortified milk.
Limit alcohol and quit nicotine; both can erode follicle quality. A review of Depo data in teenagers found bone mineral loss was partly linked to low calcium intake and sedentary habits.
Personal Factors That Shape Your Timeline
Body weight: A kinetic study on depot users showed that people with higher adipose tissue held on to the hormone longer, pushing ovulation past the eight-month mark.
Age: Ovarian reserve and pituitary feedback loops are more responsive in early adulthood. Planned Parenthood data list younger users among the first to regain cycles.
Total injections: Each dose stacks. After five or more shots, stored progestin in muscle tissue creates a longer tail. NHS guidance uses the one-year figure for that reason.
Switching From Depo To Another Method While Trying
Some switch to condoms or copper intrauterine devices once the final shot is due. The copper IUD stops sperm immediately but leaves systemic hormones untouched, so it can be removed the moment an LH surge appears.
Others pick low-dose combined pills for three months to restore predictable withdrawal bleeds.
Partner Factors And Semen Health
Depo places the spotlight on the ovary, yet semen parameters matter as much. A basic semen analysis checks count, motility, and morphology. Schedule this test in parallel rather than waiting a full year. Around 30 % of sub-fertile couples have male-side findings that benefit from early lifestyle shifts or medical care.
When Medical Care Speeds Things Up
If serum medroxyprogesterone has dropped but ovulation stalls, a clinician can prescribe letrozole at cycle day 3. In small trials on post-Depo patients, 5 mg for five days triggered ovulation in 75 % of users within two cycles.
Injectable gonadotropins are rarely needed.
CDC contraception guidance lists Depo among progestin-only options suitable for many, yet it also reminds users to plan ahead if pregnancy may be on the horizon. For drug-specific facts, scan the FDA label.
Frequently Asked Myths
“I need to detox the hormone.”
The liver breaks down medroxyprogesterone on its own. No evidence supports herbal cleanses for faster clearance.
“My period must restart before I can conceive.”
Many conceive on the first ovulation before any bleed. Periods are a marker of previous ovulation, not a prerequisite.
Takeaway
Pregnancy during or soon after Depo use is uncommon but entirely possible with the right timing. Map your last injection, track hormones rather than waiting on a period, and maintain a body that welcomes a growing embryo. If twelve months pass with no fertile signs, bring lab data to a reproductive nurse for a tailored plan. Keep hope and patience.