It depends on the model, their personal preference, and the specific job requirements. There's no single answer.
Personal Choice and Industry Trends
As supermodel Emily Ratajkowski stated in a 2019 Harper's Bazaar essay, the decision to shave armpits (or any body hair) is entirely personal. [1] While some models may choose to shave for specific photoshoots or runway shows demanding a completely smooth look, others embrace their natural body hair. [2, 3] The pressure to conform to specific beauty standards varies greatly among different agencies, photographers, and projects. A photo of a model forgetting to shave her armpits at a fashion show demonstrates that it is not always a strict requirement. [5]
Several sources mention that models may employ various hair removal methods, including shaving, waxing, or laser hair removal, depending on their personal preference and the longevity of results desired. [6, 7] However, the notion that all models shave their armpits is inaccurate. The Reddit discussion regarding men shaving their armpits highlights that not all men, and by extension, not all male models, completely shave their armpits. Instead, some trim longer hairs for hygiene or to prevent clothing soiling. [4, 9, 10]
Some argue that the "smooth underarm" look frequently seen on celebrities is achieved through a combination of pre-event waxing, photo editing, and laser hair removal. [4] This suggests that what might appear as a universal practice might be an illusion created through various techniques, and not a routine shaving practice by all models.
Conclusion
Ultimately, whether or not a model shaves their armpits is a matter of personal choice and the demands of a particular job. There's no industry-wide standard.
References:
[1] Ratajkowski, Emily. (2019). Harper's Bazaar essay (Date and specific essay title not provided).
[2] Reddit thread: Why do so many guys at the gym completely shave their armpits? r/NoStupidQuestions. Accessed [Date Accessed].
[3] Quora: Do models shave their body hair every day? Accessed [Date Accessed].
[4] Reddit thread: How do some celebrities have 100% smooth underarms? r/beauty. Accessed [Date Accessed].
[5] Facebook photo: What's On - Gambia - Gambia Fashion Night photos are out! What ... Accessed [Date Accessed].
[6] Quora: How do models get rid of body hair? Accessed [Date Accessed].
[7] GQ: Do I Need to Trim My Armpit Hair? Accessed [Date Accessed].
[8] Quora: How common is it for girls to shave their arms? Accessed [Date Accessed].
[9] The Exploress Podcast: The Hair Down There: The History of Our Relationship with Lady Hair. Accessed [Date Accessed].
[10] Quora: Why don't men shave their armpits? Accessed [Date Accessed].