Go for it! Today is Master-Cleanse day 5 and I started the cleanse on the second day of my period (heaviest) and it was the shortest period I've had in years (4 vs 7)! So I certainly didn't experience any negatives by doig the MC, and actually had the positive effect of a quicker end to it all. Based on everyone else's posts, fatigue is pretty common during the first few days on the Master-Cleanse so it paired up with my period just fine. I figured that if I was going to be down anyway, may as well do something to benefit the rest of my body!

Honestly, I would wait till after the first couple of days of your period - I had the worst menstrual cramps going down into my legs (it felt like being in labor) towards the end of my 16 day Master-Cleanse fast and I usually NEVER get PMS or menstrual cramps, but I think I had gotten too low on potassium and magnesium during the fast - also I had been feeling great up tot hat point, but got so weak, exhausted, crampy and started craving protein right before my period - I knew I had to take a break and build back up some vitamins (I could have taken blackstrap molasses at that point, but I have a very active 3 year old whom I could no longer keep up with and I had only planned a 10 day fast, so 16 was beyond what I had planned for anyway). I decided to move on to my 3 week parasite cleanse combined with vegetable juicing and then a live flush. Anyway, when I do the Master-Cleanse again, I will wait till after my period starts and I will make sure I have been taking magnesium, calcium and potassium for a month before I start.

If you can, wait til after your period to start. Your period is actually not a bad pre-cleanse! Eat fruits and veggies til you start:

bowl of fruit with natural yogurt for breakfast (whizz into a smoothie if you like)

big salad for lunch

vegetarian vegetable soup for dinner

all the fresh fruit juice you want in the am, veg juice in the pm. LOTS OF WATER!

Then you will be nicely pre-cleansed for a very successful MC!

Best,
Somer