1 citations,
December 2011 in “EFSA Journal” Spermidine may help extend the growth phase of hair.
July 2012 in “EFSA supporting publications” The EFSA maintained its view that spermidine's effect on hair growth is related to disease treatment and does not meet the health claim criteria.
March 2012 in “EFSA Journal” Iron intake has not been proven to maintain normal hair growth.
Accurate diagnosis of cicatricial alopecias requires thorough scalp examination and multiple biopsy techniques.
January 1998 in “Hair transplant forum international” I'm sorry, but I can't provide a summary as I don't have access to the specific content of the document.
1 citations,
July 2012 in “EFSA Journal” The combination of certain vitamins and pumpkin seed oil has not been proven to maintain normal hair.
September 1999 in “Hair transplant forum international” February 1970 in “Science” 
122 citations,
November 1984 in “Journal of the American Academy of Dermatology” No single treatment is consistently effective for alopecia areata, and more research is needed.
117 citations,
March 2013 in “Journal of the European Academy of Dermatology and Venereology” No effective treatment for frontal fibrosing alopecia was found, but oral 5-alpha-reductase inhibitors had the best response; for lichen planopilaris, topical corticosteroids were commonly used but had a high relapse rate.
97 citations,
September 2006 in “Pharmaceutical Research” No treatment fully prevents hair loss from chemotherapy yet.
87 citations,
December 2015 in “Cochrane library” No single treatment is clearly effective for central serous chorioretinopathy.
66 citations,
June 2018 in “International Journal of Women's Dermatology” No cure for female pattern hair loss, but various effective treatments exist.
44 citations,
April 2017 in “International Journal of Dermatology” No treatment is completely effective for alopecia totalis and alopecia universalis.
43 citations,
March 2009 in “Archives of dermatology” No treatment showed clear superiority for lichen planopilaris.
41 citations,
September 2018 in “Australasian journal of dermatology” No systemic treatment for alopecia areata has strong evidence of effectiveness.
39 citations,
April 2018 in “Hormones” No consistent link between genotype and phenotype in 5-α-Reductase type 2 deficiency.
36 citations,
May 2011 in “Dermatologic therapy” No treatments fully cure or prevent alopecia areata; some help but have side effects or need more research.
35 citations,
April 2011 in “International Journal of Dermatology” No true link between AGA and insulin resistance, but coexistence may worsen AGA.
31 citations,
August 1963 in “Archives of Dermatology” No systemic causes were found for the patients' conditions.
17 citations,
October 2017 in “Journal of Cutaneous Medicine and Surgery” No treatment has been proven to effectively stop hair loss or regrow hair in Frontal Fibrosing Alopecia, and more research is needed.
15 citations,
December 2017 in “Journal of Investigative Dermatology” No strong genetic link to other skin conditions was found, but some genetic factors may make people more likely to get seborrheic dermatitis.
15 citations,
November 2015 in “Dermatology Research and Practice” No clear link between hair loss and metabolic syndrome, but some differences in blood pressure and glucose levels.
15 citations,
June 2011 in “British Journal of Dermatology” No link found between aromatase gene and female hair loss.
13 citations,
April 2009 in “PLOS ONE” No clear link between androgen receptor variation and hair loss, but more research needed.
12 citations,
May 2010 in “PubMed” No definitive link between finasteride and male breast cancer, but further research is needed.
12 citations,
February 2001 in “Annals of Pharmacotherapy” No effective treatment for hair loss after childbirth was found, but it usually gets better on its own and some cosmetic methods might help.
10 citations,
January 2015 in “The Journal of Clinical Pharmacology” No clear link between finasteride use and acute pancreatitis risk.
9 citations,
January 2017 in “International Journal of Trichology” No current system perfectly classifies male-pattern hair loss, indicating a need for a new system for better diagnosis and treatment.
7 citations,
July 2013 in “International Journal of Dermatology” No link found between Coxsackie viruses and pemphigus.