75 Hard Supplements: What Women Actually Need (RD-Reviewed Stack)
The honest stack
For most women on 75 Hard, four supplements meaningfully improve outcomes:
- Electrolytes (daily) — sodium, potassium, magnesium
- Creatine monohydrate (3-5 g/day) — strength + brain health
- Vitamin D3 (1000-2000 IU/day) — most women are low
- Iron (only if ferritin under 50 ng/mL) — based on bloodwork
Skip the rest until you have data.
Why electrolytes are essential
The 1-gallon water rule depletes sodium and potassium faster than your food can replace them. Symptoms: headaches, fatigue, muscle cramps, brain fog. A daily electrolyte packet fixes all of them.
Look for: 500-1000 mg sodium, 200-400 mg potassium, 100-200 mg magnesium. Avoid: high-sugar sports drinks, energy drinks with caffeine added.
Why creatine is the highest-leverage optional
Creatine monohydrate is the most-studied supplement in sports nutrition. For women on 75 Hard:
- 3-5 g/day, taken any time
- Improves strength, lean mass, and recovery
- Recent research shows brain-health benefits (mood, cognition)
- No loading phase needed
- Cheapest at ~$0.25/serving
When to take iron
Only if your bloodwork shows ferritin below 50 ng/mL. Supplementing iron without low ferritin is harmful — it can cause oxidative stress and constipation.
If you're starting 75 Hard:
- Get ferritin tested
- If under 50, supplement under a doctor's guidance
- Pair iron with vitamin C, avoid coffee within 1 hour
What to skip until you have data
- Pre-workout (caffeine is fine, but specialty pre-workouts are unnecessary)
- BCAAs (use whole protein instead)
- Greens powders (eat actual vegetables)
- Fat burners (zero evidence, sometimes harmful)
- Adaptogens (mostly hype for 75-day timeframes)
The luteal-phase add-on
During your luteal week, two add-ons help meaningfully:
- Magnesium glycinate at night (200-400 mg) for sleep and PMS
- B-complex with breakfast for energy
These are optional but cheap and well-tolerated.
How to time the stack
| Time | Supplement | |---|---| | Morning | Vitamin D3 (with fat-containing food) | | With breakfast | B-complex (luteal phase only) | | Pre-workout | Caffeine if you like it; no specialty pre-workout | | Anytime | Creatine 3-5 g; electrolytes in water | | With dinner | Iron if prescribed (avoid coffee within 1 hr) | | Bedtime | Magnesium glycinate 200-400 mg (luteal phase) |
Bottom line
Electrolytes + creatine + D3 + (iron if needed) = the entire 75 Hard supplement stack most women need. Test your blood before adding more.
Related reading
Frequently Asked Questions
Do I need supplements for 75 Hard?+
Most women only need electrolytes (because a gallon of plain water depletes sodium and potassium) and possibly vitamin D and iron if bloodwork shows deficiency. Creatine is the highest-leverage optional supplement — 3-5 g/day, well-studied for women's strength and brain health. Everything else is optional.
What electrolytes should I take on 75 Hard?+
A daily packet with 500-1000 mg sodium, 200-400 mg potassium, and 100-200 mg magnesium. Popular brands: LMNT, Liquid I.V., Nuun. Drink one packet split across your gallon. During menstruation, add a second packet on heavy-flow days.
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