Am I allowed to have a special Nidah perfume?
Setting aside a perfume just for the days of Nidah wouldn’t make it permissible.
However if you wear a very small amount that doesn’t give off a strong smell that is permissible.
Sources:
ראה שערים מצויינים בהלכה ח״ד סימן קנג ס״ק כ״ג.
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