Femolin 450ml is a herbal uterotonic preparation, primarily marketed for addressing various gynecological issues. It's important to note that there seem to be different products marketed under the name "Femolin," some being homeopathic and others Ayurvedic.

Based on the information from Jayson Natural Products Ltd. (found on MedEx), the composition of Femolin Syrup (likely the 450ml variant as well) is:

• Ashok Chhal (Saraca indica): 250 mg  
• Ashwagandha (Withania somnifera): 125 mg  
• Chobchini (Smilax china): 62.5 mg  
• Olot Kombol (Abroma augusta): 62.5 mg  
• Sharpa gondha (Rauwolfia serpentina): 50 mg  
• Ferrous Sulphate:10 mg  
• Other ingredients

Indications for this formulation include:

• Irregular menstruation  
• Dysmenorrhea (painful menstruation)  
• Amenorrhea (absence of menstruation)  
• Leucorrhoea (white or yellowish discharge from the vagina)  
• Uterine weakness  
• Anemia  

The dosage mentioned for adults is 10-20 ml (2-4 teaspoonfuls), 1-2 times daily or as directed by the Physician.For irregular menstruation, dysmenorrhea, and amenorrhea, a specific dosage of 2-4 teaspoonfuls every night from the last day of the period until the first day of the next menstruation is mentioned.  

Another product, Homeopaths Femoline Syrup, has a different composition and lists its key benefitsas easing pain during the menstrual cycle, acting as a uterine tonic, potentially being useful in cases of delayed menses, and giving relief from congestion and headaches.The dosage for this homeopathic variant is Adults: Two teaspoons thrice a day with water.Or as directed by the physician.

It's crucial to check the specific label and manufacturer of the Femolin 450ml syrup you have to understand its exact composition, indications, and recommended dosage. If you are unsure, consult a healthcare professional for guidance.