Magnesium is great for pcos. Multivitamins are too of course. Inositol, chromium and NAC have great benefits too! :)

If you want a vitamin complex thats rlly good for PCOS try Fertilovit PCOS. Has all the vitamins you need

now personally i take

Flex Seed – 1,000mg
Wild Salmon Oil – 1000mg
Calcium – 333mg
Magnesium – 167mg
Vitamin D – 1,000 IU )
Chealted Chromium – 200mcg
Beta Carotene – 10,000 IU
Pacific Kelp – 650mg
Orderless garlic – 500mg
Vitamin E – 200IU
Vitamin B12 – 1,200 mcg
Vitamin B50 Complex
Vitamin B6 – 250 mg
Vitamin C – 500mg
CoQ10 – 30mg
Milk Thistle – 4,500mg
Vitamin A – 10,000 IU
Zink – 50mg
Selenium – 50mcg
Folic Acid – 1mg
Ginkgo Biloba – 2,000mg
Brewer’s Yeast – 500mg
Niacine – 500mg
Evening Primrose – 500mg

most of what I take is based off of what my Endo wants me to take for PCOS but also for other health reasons, some of it is also on the recommendation of my Diabetic Clinic and so far I can't say that its been a negative, been taking most of this on and off for the past 15 years of my life.

I've LONG list of supplements that are recorded for PCOS from varies sources - Part 1

Agnus Castus (Chasteberry)
helps with: acne, breast tenderness, infertility, irregular or absent periods, hormone imbalance, mood swings, PMS symptoms, water retention

Aloe Vera
helps with: acne, diabetes, digestive disorders, dry skin, insulin resistance, obesity

Alpha-lipoic Acid
helps with: diabetes, insulin resistance, obesity

Antioxidant complex
helps with: acne, diabetes, infertility (especially zinc, selenium), insulin resistance, irregular or absent periods (especially zinc, selenium)

Astralagus
helps with: fainting and/or dizziness, fatigue, obesity

Bitter Melon
helps with: diabetes, insulin resistance

Black Cohosh
helps with: breast tenderness, depression, hot flashes/flushes, menstrual cramps, irregular or absent periods, irritability

Blue Cohosh
helps with: anxiety, irregular or absent periods, irritability, mental fogginess

Brewer’s Yeast
helps with: fainting and/or dizziness, fatigue, food cravings, insulin resistance, mental fogginess, nervousness

Burdock
helps with: acne, excess hair

Vitamin B Complex
helps with: acne (B6), adrenal health (B5), anxiety (B1), depression (B1, B6), diabetes (B1, B3, B6), excess hair, fainting and/or dizziness, fatigue (B3, B5), food cravings, hair loss, hormonal imbalance (B6), irregular or absent periods (B6, B12), Insulin Resistance (B1, B3, B6), irritability, lack of energy (B3), liver health, mental fogginess, mood swings (B6), obesity, poor memory (B1), skin and hair problems (biotin), sleep problems/insomnia, water retention (B6)

Chromium
helps with: acne, diabetes, food cravings, insulin resistance, mood swings, obesity

Cinnamon
helps with: insulin resistance, obesity

CLA (Conjugated Linoleic Acid)
helps with: diabetes, overweight

Co-enzyme Q10
helps with: fainting and/or dizziness, fatigue, obesity

Damiana
helps with: depression, fainting and/or dizziness, fatigue, hot flushes/flashes, irregular or absent periods, mental fogginess, mood swings

Dandelion
helps with: acne, diabetes, eating disorders, fainting and/or dizziness, fatigue, irritability, obesity, water retention

Dong Quai
helps with: anaemia, fainting and/or dizziness, fatigue, hot flashes/flushes, infertility, irregular or absent periods, mood swings, PMS symptoms

Essential Fatty Acids
helps with: acne (Omega-3), appetite control, breast tenderness (Omega-3), depression (Omega-3), diabetes, eating disorders (omega-3), fainting and/or dizziness (omega-3), fatigue (omega-3), food cravings (omega-3), hair loss (omega-3), heart health, hormonal balance, infertility (omega-3), insulin resistance (omega-3), irregular or absent periods (Omega-3), irritability (omega-3), mood swings (omega-3), obesity, skin and hair problems, water retention (omega-3)

Another one I didn’t see mentioned is Lavender capsules! (I recommend CalmAid brand) helps with anxiety and also has recently been shown in NIH studies to balance progesterone levels and insulin (potentially as effective as metformin).